Uniqueness of Card Game Intervention in Improving Students’ Conceptual Understanding of Chemical Names and their Formulae

This study investigated the unique contribution of card game intervention in improving students’ conceptual understanding of chemical names and their formulae. Purposive sampling was employed to engage 45 senior high school students in an intact class. A quantitative research approach with classroom action research design was utilized as the blueprint for data collection and analysis. The instrument used for the data collection was test, which was developed by the researcher. The validity of the instrument was checked through expert review and Kuder-Richardson Formula 20 (KR-20) was applied to calculate the reliability index of the instrument, which was 0.870. The study found that before the implementation of the card game intervention, the students demonstrated various conceptual difficulties in understanding chemical names and formulae of inorganic compounds. Additionally, the findings revealed that the card game intervention was unique and highly effective in improving students’ conceptual understanding of chemical names and formulae. The study concludes that card game is a unique intervention that improves students’ conceptual understanding of chemical names and formulae of inorganic compounds. It is recommended that chemistry teachers in the selected senior high school where the study was conducted should integrate card game intervention into the teaching of chemical concepts to alleviate boredom and anxiety among students as they learn the subject.

Introduction

The formation of compound and chemical names is a fundamental component of chemistry education. The students’ understanding of these basic chemical concepts is crucial for their progression in chemistry education. In this era, chemicals are prevalent, and it is very important to recognize chemical compounds by their names and chemical formulae for an informed appreciation of chemical concepts (Prashant & Gowri, 2020). A chemical formula is perceived as a set of elemental symbols and subscript numbers that represent the composition of a substance (Amazona & Vallejo, 2020). Students’ comprehension of chemical names and formulae help them to study other chemistry topics with ease.

The International Union of Pure and Applied Chemistry’s (IUPAC) Nomenclature Committee established guidelines for naming chemical substances (Baah & Anthony-Krueger, 2012). These guidelines are essential for providing the correct chemical name and chemical formula for any given inorganic compound. The names of compounds and their formulas form the basis for students to comprehend future chemistry concepts that are vital to them and science at large. Knowledge of elements, atomic number, electron configuration, charge formation (cations and anions), valence electrons, and oxidation numbers is imperative for students to understand chemical names and their corresponding chemical formulae. Before writing a balanced chemical equation, students need to learn IUPAC nomenclature, elements, and symbols to develop chemical formulae (Ogundiji, 2024).

Although chemical names and chemical formulae are basic requirements for understanding several other chemistry topics, students at various levels of their education have difficulty comprehending these essential chemical concepts. The use of chemical symbols, formulae, chemical equations, and calculations involving moles are areas where beginners experience the most difficulties (Dula, 2018). Dula concluded that success in learning chemistry depends on the learners’ competency in basic chemistry concepts. When students struggle to conceptualize basic scientific concepts, learning becomes a barrier, and they become easily irritated when they do not understand what is taught during the teaching and learning process (Yaayinet al., 2022). It is always frustrating and discouraging when students struggle to understand concepts that are needed to lay the foundation for further study of related concepts. Students’ inability to correctly name inorganic compounds has long been a source of concern for the West African Examination Council (WAEC), which oversees the examination administration in West Africa (Baah & Anthony-Krueger, 2012). The identity of a compound can be drastically changed by a minor error in the writing of the chemical formula or by a deviation from the rule of conservation of mass; therefore, accurate attention to detail is necessary while balancing chemical equations (Ogundiji, 2024).

Taskin and Bernholt (2014) claimed that conceptual links between the macroscopic, microscopic, and symbolic levels of understanding and writing chemical formulae and compound names are usually linked to difficulties in computing correct chemical equations. Just as the atoms of elements cannot be seen and touched, it becomes difficult to conceptualize them and relate their occurrence to everyday life. The notion that chemical knowledge may be produced, communicated, and taught at three levels – macroscopic, sub-microscopic, and symbolic–is one of the most powerful and productive concepts in chemical education that supports students’ understanding (Ballester Pérezet al., 2017). Deleña and Marasigan (2023) highlighted that writing chemical formulae and using chemical nomenclature are two symbolic teachings in chemistry. They compared this to NaCl, which is represented at the symbolic level as NaCl. Because chemistry is taught at a symbolic level, learners find it difficult to comprehend it. Chemistry involves many abstract concepts based on theoretical knowledge, which are usually discussed and taught primarily in terms of theories and non-observable processes (Taber, 2019).

Despite attempts by researchers to resolve these problems through various interventions, these problems persist. Garrido-Escudero (2013) posited that students usually face five challenges in learning chemical nomenclature due to unfamiliarity with the periodic table and elements, inadequate knowledge regarding element electronic configurations and oxidation states, challenges associated with identifying chemical compound types, lack of understanding of IUPAC nomenclature, and its rules and challenges in interpreting the meaning of a chemical formula or its name. Students’ attitudes towards naming inorganic compounds and writing chemical formulae heavily influence their level of comprehension of chemical concepts. Most beginners in science deem chemical nomenclature and the rules set forth by IUPAC hazy; thus, they feel reluctant to even delve deep and understand. According to Yaayinet al. (2022), students’ attitudes towards learning science concepts are just as significant as their comprehension of such concepts, which makes them a powerful predictor of what they can accomplish within the learning paradigm. Teachers’ methods of instruction had a significant impact on students’ attitudes towards chemistry. According to Musengimanaet al. (2021), teaching strategies impact students’ perceptions of chemistry. The teacher is seen as one who translates chemistry curriculum goals into classroom learning experiences and activities. This becomes a big problem in the learning paradigm when the teacher assumes the role of a transmitter of knowledge instead of a facilitator.

Research has shown that card games encourage problem-solving, teamwork, and active learning (Dankbaaret al., 2017). Card games are used to teach topics in organic chemistry, engineering, materials science, and inorganic nomenclature at all levels (Franco-Mariscalet al., 2012; Kurushkin & Mikhaylenko, 2015). Similarly, studies have revealed that card games have been utilized as didactic tools to teach and reinforce chemistry in classrooms in recent years (Camarcaet al., 2019; Erlinaet al., 2018; Gogalet al., 2017). Using cards with the chemical formulae of various inorganic chemical compounds printed on them, Buendía-Atencioet al. (2022) employed the Werner card game, which is named after Professor Alfred Werner, to reinforce the learning of inorganic nomenclature. Werner incorporated new chemical elements into the IUPAC systematic nomenclature. Card games have been found to significantly improve students’ performance, as Najdi and El Sheikh (2012) discovered that after playing educational games, students have a more positive attitude towards learning chemistry.

Owing to the intricacies of the previous system for identifying chemical compounds, the International Union of Pure and Applied Chemistry (IUPAC) introduced a new system to replace it. Because students can easily translate a chemical compound’s name to its formula, the new method has the advantage of being versatile. Despite these advancements, students still frequently struggle with naming and writing chemical formulae, particularly inorganic compounds. Therefore, it has become essential to employ friendly and interesting teaching strategies that will assist students in the IUPAC system in naming inorganic compounds and writing their formulae. Although, the use of card games as an instructional approach has been explored in other studies, there is a contextual gap regarding the use of card games to teach chemical names and formulae of inorganic compounds in senior high schools within the study area in Ghanaian senior high schools. A study only focused on investigating senior high school students’ difficulties and understanding in naming inorganic compounds by IUPAC nomenclature but did not explore any innovative approach to remedy the situation (Baah & Anthony-Krueger, 2012). Thus, this study was guided by the following research objectives: (1) to assess students’ conceptual difficulties in understanding chemical names and formulae of inorganic compounds and (2) to determine the effect of card games on students’ conceptual understanding of chemical names and formulae of inorganic compounds.

Literature Review

The foundation of this study, which sought to use a card game to improve students’ conceptual understanding of chemical names and formulae, is hinged on social constructivist theory. According to Piaget (1962), young children’s informal games are essential for their social and intellectual growth. Theoretically, games that are social activities can be used to teach and learn chemistry, as this approach aligns with Vygotsky’s (1978) zone of proximal development hypothesis, which is the range of tasks that a learner can perform with the support of a more knowledgeable colearner. The significance of games in chemistry teaching lies within the tenets of social constructivism, where students learn through collaboration, creativity, and critical thinking. By making learning “fun” and promoting peer interaction, educational games are specifically created to be utilized as a teaching tool to boost students’ motivation to study (Rastergarpour & Marashi, 2012).

From the literature, various issues have been identified that hinder students’ conceptual understanding of the chemical names and formulae of inorganic compounds. First, there is a stress on scientific representation (macroscopic, sub-microscopic, and symbolic) levels as the source of students’ difficulties in naming inorganic compounds and writing chemical formulae (Ballester Pérezet al., 2017; Deleña & Marasigan, 2023; Taskin & Bernholt, 2014). Again, Dula (2018) based his argument on the lack of chemistry language skills and Taber (2019) related students’ challenges to the abstract nature of chemistry.

The findings from the study conducted by Baah and Anthony-Krueger (2012) identified the inability of students to write the correct names of some elements in compounds, difficulty in determining the central atom, and calculation of the oxidation numbers of central atoms in compounds as some of the difficulties found with the systematic naming of inorganic compounds. Evidence from previous research, coupled with the Chief Examiner’s report in chemistry regarding students’ inability to answer questions on chemical nomenclature and the writing of correct chemical formulae, suggests the need for further research in this area of chemical knowledge. Studies have shown that students have difficulties in distinguishing between subscripts, which illustrate the atomic quantity within a molecule or a compound, and coefficients, which represent the quantity of molecules or compounds in a chemical reaction (Hamerskáet al., 2024; Johnstone, 2022). As a result, students use subscripts and coefficients interchangeably, which creates confusion in their understanding of the chemical names and formulae of inorganic compounds. Similarly, understanding valency, comprehending the crisscross method, and the ability to identify polyatomic ions remain substantial challenges among students (Chiu, 2021). As part of the difficulties that students encounter in understanding chemical names and formulae, Boujaoude and Barakat (2022) posited that students often misrepresent ionic compounds as charge entities instead of neutral compounds. Additionally, students’ insufficient mathematical abilities make it difficult for them to write the correct chemical formulae (Baah & Ampiah, 2012).

The problems related to abstract and difficult topics in chemistry have led researchers in chemical education to formulate teaching and learning activities, either inside or outside the classroom, to rectify this challenge (Cardellini, 2012; Franco-Mariscalet al., 2016; Romanoet al., 2017). According to Presetyo and Irwanto (2015), chemistry at the senior high school level is extremely challenging for students to understand because it involves abstract or microscopic concepts, chemical reactions, and calculations, all of which can be confusing to these students. To overcome these challenges, a didactic approach that serves as the foundation for fostering students’ interest in chemical principles and inspiring them to enjoy the subject on an intrinsic level must be employed.

Lutfi and Hidayah (2018) asserted that there is a relationship between students’ motivation to learn and their level of achievement. Teachers must be able to motivate students to learn to raise their accomplishments (Rakhmadhaniet al., 2013). A supportive and enjoyable learning atmosphere and engaging in activities, such as games, can help teachers create an extrinsic drive in their students about chemistry.

In general, identifying chemical compounds entails determining how symbols, ions, formulae, and their names relate to one another, translating the name into its constituent ions, and merging the ions into the appropriate formulae (Etokeren & Abosede, 2021). This can be accomplished through games. Morris (2011) created the well-known game “Go Chemistry,” which was created to assist with a variety of tasks, including identifying the chemical symbols of elements and ions, classifying elements into metals and nonmetals, and applying the nomenclature rules in naming compounds. Using a “One-Group Pretest–Posttest” design and a motivation questionnaire as an instrument, Lutfi and Hidayah (2018) investigated the impact of an online Chemmy card 6-1 game as a teaching tool in IUPAC nomenclature of inorganic compounds for X grade 6 and 7 senior school students at SMA Negeri Sidoajora, Indonesia. The study’s findings showed that teaching the IUPAC nomenclature of inorganic compounds through the Internet-assisted Chemmy card 6-1 game significantly improved students’ achievement and learning goals. As they listened to the teacher’s explanations and provided accurate answers to the questions, the students demonstrated a high level of motivation and engagement.

Methodology

Research Approach and Design

The quantitative research approach and action research design were utilized as blueprints for data collection and analysis in this study. Within the quantitative research approach, numeric data were collected using pre- and post-intervention tests through three phases of action research design: pre-intervention, intervention, and post-intervention phases.

Research Instrument

The instrument employed for data collection in this study was developed as a pre-intervention test and a post-intervention test by the researcher. Although not the same test items or questions, the structure and level of difficulties of the pre-intervention and post-intervention tests were the same. This was meant to avoid threats to internal validity, as the mean of the pre-intervention test was compared with the mean of the post-intervention test to determine students’ conceptual understanding of the chemical names and formulae of inorganic compounds, resulting in the implementation of the card game intervention. The validity of the instrument was checked through an expert review, as both face and content validity were ensured. The Kuder-Richardson Formula 20 (KR-20) was used to calculate the reliability index of the instrument to ascertain its appropriateness before it was used to collect the data. KR–20 was used because it measures the internal consistency of the test items. In addition, the test items had varying difficulty levels and could only measure correct or incorrect answers. Twenty students who were not part of the study participants, but shared similar characteristics with them, were engaged in responding to the test items, which were marked, and the scores collated to determine the reliability of the instrument using the KR-20. The reliability index was 0.870, indicating that the instrument was reliable.

Sampling and Sampling Technique

Purposive sampling was used to engage 45 students in an intact class, as this study was a classroom action research approach. Senior High School Year Two Agricultural Science students at a selected school in Gomoa West District of Central Region studied chemistry as an elective subject and had difficulties in understanding chemical names and formulae of inorganic compounds. The concept of chemical names and formulae of inorganic compounds has already been taught through the traditional teacher-centered approach, yet students still indicate various levels of misunderstanding of the topic. With background knowledge of the topic, students in an intact class were selected for the study.

Data Collection Procedure

Following the blueprint of the action research design, the data collection procedure encompassed three phases: pre-intervention, intervention, and post-intervention. In the pre-intervention phase, although students’ difficulties in understanding chemical concepts regarding chemical names and formulae of inorganic compounds were identified by the class teacher through years of experience teaching, a pre-intervention test was conducted to further ascertain the difficulties.

Students’ difficulties in this topical area cut across different levels among students studying chemistry in senior high schools. The focus of this study was centered on a particular intact class of one of the selected senior high schools in Gomoa West District of Central Region, Ghana, where students exhibit varied difficulties in the topic. This group of students offers a general agricultural science program in which chemistry is studied as an elective subject.

In the intervention phase, a card game was used to actively and creatively engage students in learning the chemical names and formulae of inorganic compounds. The intervention was implemented within two weeks, and the following areas of the chemical concepts were taught with the aid of card games: elements and their symbols, atomic numbers and electron configuration, valence shells and valence electrons, formation of charges (cations and anions), identification of cations, anions, and radicals, combination of cations and anions to form neutral compounds, and chemical names and their corresponding formulae. The 45 students in the intact class were put into nine groups, with five students in each group during the intervention through card games. The groups formed were mixed ability and gender responsive.

Some examples of various cations and anions combined to form chemical formulae with their respective chemical names are shown below. Fig. 1 shows the formation of sodium hydroxide from sodium and hydroxyl ions using the card game strategy.

Fig. 1. Combination of Sodium ion and hydroxyl ion to form sodium hydroxide.

As shown in Fig. 1, the correct formation of sodium hydroxide is indicated as sodium ion combined with hydroxyl ion. Sodium with atomic number 11 has a valency of one and forms a Lewis dot symbol, as shown in Fig. 1. This means that the sodium ion donates one electron, which is gained by the hydroxyl ion, to form sodium hydroxide.

Similarly, Fig. 2 shows the formation of magnesium oxide from magnesium and oxygen ions (oxides).

Fig. 2. Combination of magnesium ion and oxygen ion to form magnesium oxide.

As shown in Fig. 2, magnesium with atomic number 12 has two valence electrons, which can readily be lost and gained by oxygen to form magnesium oxide. It is expected that in the card game, the students are able to match the cations correctly with the anions to form the required product, being magnesium oxide (MgO).

Furthermore, radicals that form both positive and negative charges can also combine to form the required compound, showing its correct chemical name and formula, as illustrated in Fig. 3.

Fig. 3. Combination of ammonium ion and nitrate to form ammonium nitrate.

The ammonium ion as a radical has a charge of +1, meaning it releases one electron that has been accepted by the nitrate as another radical with a charge of −1 to form ammonium nitrate, as shown in Fig. 3. In the card game, students are expected to apply their knowledge of elements and symbols, atomic numbers, electron configuration, valency, charge formation, radicals, and balancing of charges to match cations and anions correctly to form the required chemical compounds with their correct chemical names and formulae.

Fig. 4 shows the implementation of the card game during the intervention as students interact among themselves in groups to learn the correct formation of chemical formulae and provide the appropriate chemical names.

Fig. 4. Cations, anions and radicals used as card game to teach students. Source: Field survey (2025).

As shown in Fig. 4, a card game was played during the intervention to teach students the concept of chemical names and formulae of inorganic compounds. The cards were cut into different shapes, as shown in Fig. 4, to represent various cations, anions, and radicals, including the main group elements and transition elements. At the group levels, students fixed the cut-out cards together to form correct chemical formulae with the correct chemical names. Groups that were not able to perform the tasks correctly during the game, were assisted by the teacher and peers to accomplish the tasks appropriately.

In the post-intervention phase, a test was conducted to assess students’ conceptual understanding of the topic. This was done to ascertain whether students improved their understanding of chemical names and formulae after the intervention using the card game teaching approach.

Data Analysis Procedure

Descriptive and inferential statistics were used with Microsoft Excel version 20 to analyze the data. From students’ responses in the pre-intervention test, percentages were used to quantify the number of students with challenges regarding their understanding of various conceptual areas of chemical names and formulae. Again, a paired samples t-test was used to compare the mean performance of students on the pre- and post-intervention tests to determine the improvement in students’ understanding of the concepts taught because of the effect of the card game intervention. The eta-squared value was calculated to ascertain the effect size. The guidelines according to Cohen (1988) for interpreting the eta squared values are that 0.01 to 0.05 indicate a small effect while 0.06 to 0.13 show a moderate effect and 0.14 and above denote a large effect.

Ethical Consideration

A letter was collected from the Department of Chemistry Education, University of Education, Winneba, which guided the researcher to seek permission from the management of the selected senior high school in the Gomoa West district of the Central Region, Ghana, where the study was conducted. After permission was sought through the management of the institution, the consent of all participants (students) was sought before they were engaged in the study. Participants were assured of a high level of confidentiality in keeping data related to this study, and anonymity was upheld in this study as the identity of no student was disclosed during data collection, analysis, and publication. Participants were not coerced to participate in the study as they were informed of the purpose of the study. Participation in the study was voluntary.

Results and Discussion

Results

The results are presented based on two objectives formulated to guide this study. The results are presented followed by a discussion of the findings.

Assessment of Students’ Conceptual Difficulties in Understanding Chemical Names and Formulae

This section presents the results and discussion based on the objectives the researcher sought to achieve in this study. Table I shows the descriptive statistics of students’ performance on the pre-intervention test, based on which their conceptual difficulties in understanding chemical names and formulae were assessed.

Table I. Descriptive Statistics of Students’ Performance in Pre-Intervention Test

Test	N	M	SD	CV (%)	Mode	Range	Min.	Max.
Pre-intervention Test	45	35.8	10.7	29.9	33	43	12	55

As shown in Table I, the mean score on the test was low (M = 35.8), and the total score on the test was 60. The results showed that the scores of most of the students were around the mean, as the modal mark was 33. Even though the minimum score was 12 and the maximum score was 55, with a range of 43, the variability of the students’ scores was uniform or homogeneous because the coefficient of variation (CV = 29.9%) was low. This means that very few students had extremely low scores (min. = 12), or a high score (max. = 55). With a mean score of 35.8 far lower than the total score of the test, the students had difficulties in understanding concepts related to chemical names and formulae of inorganic compounds. This was buttressed by the low coefficient of variation, indicating that most of the students demonstrated similar characteristics in terms of their level of understanding of the chemical names and formulae of inorganic compounds.

Fig. 5 illustrates some extracts of students’ responses to the pre-intervention test items, indicating their low performance and conceptual difficulties in understanding chemical names and formulae.

Fig. 5. Extracts of students’ responses to some pre-intervention test items. Source: Field data (2025).

Fig. 5 shows that the students’ difficulties in understanding chemical names and formulae include their limited knowledge of the oxidation states of elements in a given compound; their inability to identify cations, anions, and radicals in a given inorganic compound; and interpretation of subscripts for individual elements in inorganic compounds to mean their charges or oxidation states. Consequently, instead of naming K₂S potassium sulphide, it was named potassium (II) sulphide. Cu₂O should have been named copper (I) oxide; however, the students named it copper (II) oxide. Again, the charge of Fe in Fe₂O₃ should be +3 but not +2, as indicated by the students’ responses, as shown in Fig. 5.

Some open-ended extracts of students’ responses to the pre-intervention test items are shown in Fig. 6.

Fig. 6. Extracts of students’ responses to some pre-intervention test items. Source: Field data (2025).

Fig. 6 reveals that some students could not deduce the symbols and respective cations and anions from a chemical name and could not write the corresponding chemical formula from a given chemical name. Instead of MgO for magnesium oxide, it was written as MgO²⁺ and instead of CO₃²⁻ for carbonate, it was written as O²⁻. Again, instead of S²⁻ for sulphide, it is written as S³⁻. symbol and charge of magnesium are written as Na⁺ instead of Mg²⁺. The study found that students have difficulties in understanding concepts such as electron configuration, leading to the determination of cations and anions for given elements and the identification of chemical formulae from their respective chemical names, as shown in Fig. 6.

Students’ conceptual difficulties in understanding chemical names and formula formation varied, as Fig. 7 shows how one of the participating students in the study responded to an open-ended question that sought to assess students’ understanding of chemical names and their respective formulae.

Fig. 7. Extract of students’ response to a pre-intervention test item. Source: Field data (2025).

As indicated in Fig. 7, the particular student who responded to this question had conceptual difficulties understanding the concept of a radical, that is, a group of atoms that stay together as a charge unit. The student also took subscripts that represented the atoms of elements in the compound as valencies. In this question, students were asked to deduce the chemical formula of ammonium sulphide. Instead of (NH₄)₂SO₄, the answer given by the student was NH₄(SO)₄ because ammonium has 4 valence electrons and sulphate has valence electrons. The explanation given by the student clearly shows that there is a conceptual difficulty in understanding how radicals that are positively charged combine with radicals that are negatively charged to form inorganic compounds. The student in this context lacks the understanding that ammonium as a radical is represented as NH₄⁺ and sulphide as a radical is represented as SO₄²⁻. Therefore, to balance the charges to obtain a neutral compound for ammonium sulphide, a coefficient of 2 is needed for ammonium, which is written as a subscript in the chemical formula as (NH₄)₂SO_4. Generally, students are confused about how coefficients are used to balance charges and how they are used as subscripts in compound formations. As indicated earlier, the extracts are only a few examples that depict students’ conceptual difficulties in understanding chemical names and formulae. Several issues were identified in their responses to the pre-intervention test items, which led to their poor performance.

Effect of Card Games on Students’ Conceptual Understanding of Chemical Names and Formulae of Inorganic Compounds

Table II presents both descriptive and inferential statistics showing the performance of the students in the pre-intervention test and the post-intervention test.

Table II. Students’ Performance in Post-Intervention Test after Card Game Intervention

Test	N	M	SD	Mode	Range	Min.	Max.	df	t	p	η2
Pre-intervention Test	45	35.8	10.7	33	43	12	55	44	3.3	0.002*	0.198
Post-intervention Test	45	43.0	8.7	47	37	21	58

In Table II, the results show an improvement in students’ performance on the post-intervention test (M = 43.0, SD = 8.7, Mode = 47) compared to the pre-intervention test (M = 35.8, SD = 10.7, Mode = 33). The improvement in students’ performance was significant (p = 0.002) due to the implementation of the card game intervention. Again, the magnitude of the effect of the card game intervention on the students’ conceptual understanding of chemical names and their formulae was large, based on the eta squared value (η² = 0.198). Thus, this study found that the card game intervention was effective in improving students’ conceptual understanding of chemical names and formulae of inorganic compounds with a large effect size. Most students scored above 40 (modal mark = 47) out of a total score of 60 in the post-intervention test.

Discussion of Findings

Students’ Conceptual Difficulties in Understanding Chemical Names and Formulae

This study found that before the implementation of the card game intervention, the students had low performance on the pre-intervention test, as the mean score (M = 35.8) was far lower than the total score of the test, which was 60. This shows that the students demonstrated various conceptual difficulties in understanding the chemical names and formulae of the inorganic compounds. Typically, some students cannot write the correct chemical formulae for ammonium sulphide, magnesium oxide, magnesium nitride, sodium sulphide, and sodium nitrate. Some students could not deduce chemical names for chemical formulae, such as Cu₂O, K₂S, and Fe₂O₃. Similarly, students could not identify cations and anions from chemical names, such as magnesium nitride, sodium sulphide, and ammonium sulphide.

Students’ conceptual difficulties in this regard cut across their lack of understanding of basic concepts relating to the chemical names and formulae of inorganic compounds, as revealed in their responses to the pre-intervention test items. These difficulties focus on students’ inability to form correct charges (cations or anions) from neutral atoms due to their lack of understanding of the concepts of electron configuration and valency. There is also confusion between charges and subscripts used in determining chemical formulae, and chemical names as a subscript to a particular element in a compound are taken to mean its charge. For example, the charge on iron in Fe₂O₃ is +2 instead of +3. Students also had difficulty balancing cations and anions in an ionic equation to determine the formation of chemical formulae. Additionally, students had difficulty understanding that transition elements have variable oxidation states that are usually considered when determining chemical names and formulae.

The finding in the current study that focuses on students’ difficulties in understanding the oxidation states of both the main group and transition elements that are useful in determining chemical names and formulae corroborates the study of Baah and Anthony-Krueger (2012). In their study, they emphasized students’ difficulty in determining the central atom and calculating the oxidation numbers of central atoms in compounds as some of the difficulties found with the systematic naming of inorganic compounds. As students fail to conceptualize the oxidation states of elements in inorganic compounds, it becomes difficult for them to write the correct chemical names and formulae. These are fundamental concepts in chemistry that students need to comprehend to learn more topics in the subject. Again, the findings of this study reveal that students have inadequate knowledge of electron configuration, charge formation, and valency, which is consistent with the studies of Garrido-Escudero (2013) and Chiu (2021), who posit that students have insufficient knowledge regarding element electronic configurations, valency, oxidation states, and the use of a crisscross method that hinders their understanding of chemical names and formulae.

Additionally, findings of previous studies have shown that students have difficulties in distinguishing between subscripts, which illustrate the atomic quantity within a molecule or a compound, and coefficients, which represent the quantity of molecules or compounds in a chemical reaction (Hamerskáet al., 2024; Johnstone, 2022). These findings are in agreement with the findings of the current study, in which students demonstrated misunderstanding between charges and subscripts being used in determining chemical formulae, and chemical names as a subscript to a particular element in a compound is taken to mean its charge. This shows how students use subscripts and coefficients interchangeably, which creates confusion in their understanding of the chemical names and formulae.

Effect of Card Game in Improving Students’ Understanding of Chemical Names and Formulae

This study found that the card game intervention improved students’ conceptual understanding of chemical names and formulae. The mean score of students’ performance in the post-intervention test was significantly higher than that in the pre-intervention test. The findings also revealed that the magnitude of the effect of the card game intervention on students’ conceptual understanding of chemical names and formulas was large.

The uniqueness of the card game intervention in improving students’ conceptual understanding of chemical names and formulae stems from the fact that games motivate and sustain their interest in learning. Games embedded with scientific concepts enable students to learn through collaboration, creativity, problem solving, and critical thinking. This aligns with a previous study that found that card games are good at encouraging problem solving, teamwork, and active learning (Dankbaaret al., 2017). These 21^st century skills are critical for improving students’ understanding of chemical concepts. Many science classrooms, especially those of chemistry, are too tensed because of the abstract aspects that students are obliged to learn. In this regard, games integrated with scientific concepts become game-changers in relaxing the minds of students and stimulating their interest in learning chemical concepts that are seemingly difficult with ease. In this study, students were actively engaged in learning various chemical concepts embedded in card games, such as elements and their symbols, electron configuration, cations and anions, valencies, chemical combinations of cations and anions to form various inorganic compounds, providing chemical names for given chemical formulae, and vice versa. The class teacher was less engaged and served as a facilitator, and the students were more engaged in the learning process as they learned.

The findings in the current study, as the card game intervention improved students’ conceptual understanding of chemical names and formulae, support the findings of previous studies that found games to enhance students’ understanding of chemical formulae, identification of chemical symbols of elements and ions, classifying elements into metals and nonmetals, and applying the nomenclature rules in naming compounds (Etokeren & Abosede, 2021; Morris, 2011). Similarly, the findings of this study align with those of Lutfi and Hidayah (2018), who found that teaching the IUPAC nomenclature of inorganic compounds through the Internet-assisted Chemmy card 6-1 game significantly improved students’ achievement and learning goals. The uniqueness of card games cannot be overestimated, as they improve students’ conceptual understanding of chemical names and formulae of inorganic compounds.

Conclusion

This study concludes that prior to the implementation of the card game intervention in teaching chemical names and formulae in the selected senior high school, students had difficulties understanding chemical concepts relating to chemical names and formulae of inorganic compounds. This situation led to students’ low performance in the pre-intervention test that assessed their conceptual understanding of chemical names and formulae. The conceptual difficulties encountered by the students in this study focus on their inadequate knowledge in identifying cations and anions in given compounds, the concept of electron configuration and valency, and confusion in differentiating between coefficients, subscripts, and ionic charges in given compounds and ionic equations.

The study also concludes that card games are unique interventions that improve students’ conceptual understanding of the chemical names and formulae of inorganic compounds. The card game is unique in this study, as the magnitude of its effect on students’ conceptual understanding of chemical names and formulae is large, and it is capable of stimulating and sustaining students’ interest in learning chemical concepts.

Limitations

As the study was classroom action research that engaged an intact class where participants were selected by purposive sampling, the findings of the study cannot be generalized. Again, generalizability of the findings was limited due to the absence of a control group and a small sample, which was non-randomized.

Recommendation

The researcher recommends that chemistry teachers in the selected senior high school where this study was conducted integrate card game intervention into the teaching of chemical concepts to alleviate boredom and anxiety among students as they learn the subject.