Model-based learning about structures and properties of chemical elements and compounds via the use of augmented realities

Organic molecular structure app

The Organic Molecule AR/VR cards the current research developed is the only application in the app market that features both learning and game play. It is available with three different decks of cards. The manual and the QR-code download link for the app can be found on the cards. One can also search for Molecules 1 AR/VR, Molecules 2 AR/VR & Molecules 3 AR/VR in the Apple App Store (10+) or Google Play in Android devices (6.0+). Information can also be found on the website of Chemical Society Located in Taipei (http://www.chemistry.org.tw/app_download.php). Some descriptions of these apps were published in Chinese at www.chemed.chemistry.org.tw. (Please see Chiu, Chou, Hung, & Hsu, 2018).

The Organic Molecule AR/VR cards were designed mainly with the organic compounds found in local high school textbooks in Taiwan. The three decks of cards are based on the functional groups. The first deck is consisted of hydrocarbons, namely alkane, alkene, and alkyne. The second deck includes alcohol, ether, and ketone. The third includes acid, ester, amine, and amide. The chosen organic compounds in each deck are various chemical compounds and their isomers, appeared in the textbooks. For example, with a carbon number of 4, there are 1-butene, cis-2-butene, trans-2-butene, and 2-methylpropene (as shown in Figure 1). Figure 2 shows the chemical compounds with the same functional group (-COOH), there are formic acid and acetic acid (as shown in Figure 2).

Figure 1:

Isomers for C₄H₈.

Figure 2:

Homologues of the same functional group.

In addition to showing organic molecules’ three-dimensional structures, the main concepts the cards intend to convey also includes isomers and homologues. Through these cards, the students develop interest in learning and a deeper understanding of symbols, chemical equations, properties, structures, and conversion between 2D and 3D structures (see data analysis in later sessions).

As described above, the app for Organic Molecule AR/VR cards, with its AR technology, can assist teachers to better present and explain the 3D structure and characteristics of organic molecules. Students can also manipulate the molecules through touchscreen or joystick for a better view of the molecule’s structure. Furthermore, with its VR technology, students can be assessed on what they have previously learned in class regarding molecular structures through a virtual computer game scenario. In the game, students have to complete a mission of finding the structures of organic molecules (such as alkanes, alkenes, or alkynes) within a limited time frame (300 s). This scenario features gaming elements such as time limit for the mission, rewards and punishment during game play, and feedback at the end of the mission (see Figure 3). Once a student finds three assigned compounds, they are allowed to get into the next stage for another group of organic compounds. Players need to complete the assigned task within 5 min. The player can gain an extra 10 s if they find a gem in the game. Research indicates that learning through gaming would make learning gaining a wide range of cognitive, perceptual, behavioral, affective and motivational impacts and outcomes (Connolly, Boyle, MacArthur, Hainey, and Boyle 2012).

Figure 3:

VR game for organic molecules. (A) Molecular Structure AR mode. (B) VR Game Play Scenario. (C) The mission to gather molecules with –OH functional group. (D) Monster appears if the wrong molecule was selected. (E) Gathering jewels to extend working time. (F) Feedback when the mission is accomplished.

The app has three modes of game play (see Figure 4), each was designed to be used with a specific deck of cards. There are two modules in each mode. The first module enables the player to observe the 3D structure and characteristics of every organic molecule through the AR module of the software. The second is an assessment of learning outcome in a gaming scenario. This assessment can only be accessed by selecting a VR label on the screen, which is only accessible through the card’s AR mode screen once the player has gained sufficient knowledge about each type of molecules.

Figure 4:

Selection for the three modes of game play.

There are three main ways to use the app:

1. Direct Observation: Teachers can ask students to scan the cards with the app and compare how the structure of the 3D molecule shown on the mobile device is different from those shown on the 2D card. AR would allow students to rotate the 3D molecular structure to a perspective where it would look the same as those shown on the card or books. Students would then be able to take a screenshot and upload it to the cloud storage the instructor had prepared. Finally, students can share their ideas and screenshots with their peers for discussions. It is hoped that students would learn how the 3D organic molecular structure is related to the structural formula and 2D representations. In this process, the instructor may also select specific cards (such as finding isomers or homologues from the same functional group) and ask students to draw or point out the relative spatial position of atoms.

2. Learning sheets: Instructors may utilize designs similar to those from the table below to conduct their instructional activity (see Figure 5), and ask students to fill in the chemical equations and name the compounds they observe on the app. The learning sheet can be downloaded from the dedicated app instructional material page on the CCS Located in Taipei website (http://www.chemistry.org.tw/app_download.php#pagefive).

Figure 5:

AR Assessment for organic compounds. (a) Original worksheets. (b) Modified version of worksheet for assessment.

Instructors may reorganize the learning sheet (see Figure 5) according to the organic chemistry content he/she intends to teach. Students may use the app to scan the learning sheet, observe the 3D structures and write down their structural formulae (Figure 5A). Or, the instructor may simply list the compounds’ IUPAC naming and its related codes, such as pentane, 2-methylbutane, 2,2-dimethylpropane, and ask the students to write down their corresponding structural formulae, followed by a grouped discussion on the relationship between the IUPAC naming and the structural formulae (Figure 5B). Figure 5B can be used for various purposes in chemistry teaching through providing different hints or information of the molecules on the cards. By drawing the structures of the compounds, students would be able to practice how to transform 3D representations of the chemical compounds to 2D representations and vice versa.

We have been using these packs of poker cards of organic compounds in a senior high school in Taipei city for many years. In one of the classes, the students expressed positive attitudes toward the use of AR in learning chemistry in their interviews. Their responses are as follows:

1. 82 % (18/22) of the students stated that they appreciated the use of mobile phones in learning science since it allowed them to visualize and manipulate the chemical compounds.

2. 86 % (19/22) of the students stated that their interest in learning science increased after using ARs.

As for the teachers who participated in our workshops or e-questionnaire, they expressed that it was relatively easy to describe the complex and abstract concepts to students via the app compared to textbooks or other resources. The biggest difference between ARs and traditional teaching style is the visualization of the concepts that were difficult to convey to students through 2D representations. However, it was still challenging for teachers as they try to help students convert scientific concepts into 2D and 3D representations. They also suggested to make the game more challenging, providing students opportunities to solve problems by integrating their newly learned knowledge.

1. Board Game: The first deck of cards: Hydrocarbons, can be used as a card-based board game. Instruction can be found online at: https://goo.gl/E13011.

1A and 7A groups in the periodic table

Another set of AR was developed and titled AR_Elements (1A, 7A). Based upon research in the area of multiple representations, various forms of molecules were considered. This function of the AR app allows students to observe the structures and symbols of the 1A and 7A elements and manipulate the cards to explore the electronic structure of atoms of elements 1A and 7A.

Figure 6 describes the cards, ways to get the app, and the instruction for the operation of the app. The app was created via the software of Jmol. The app included various forms of representations of atoms and molecules. For instance, red and white balls are atom representations with standard atomic radii while the blue dots are valence electrons. In the molecular and ball-and-stick models, the size of these balls does not realistically take into account the spatial distribution of valence electrons for each type of atoms. Only the ball sizes of the van der Waal model accurately describe the three-dimensional electron cloud distribution based upon the electron – electron interaction point of view. As shown in Figure 6F, the size difference between two different atom types can be quite dramatic, making it difficult to visualize.

Figure 6:

ARs for 1A and 7A chemical elements in the Periodic Table. (A) Search for AR_Element (1A, 7A) at Google Play. (B) Download App and click to start. (C) Select the lower left corner icon to download cards once the app has been started. (D) The front side of the card is the information on 1A, 7A atoms. (E) App Interface Instruction. (F) Using the app to scan the back of card would render the AR model of the atom. (G) By placing two cards that can be combined next to each other, the combined molecular model would be shown. (H) Switching to the Lewis Model. (I) Switching to the ball-and-stick model. (J) Switching to the Van der Waals model.

Students can try to form molecular models by combining two cards (e.g. by combining the cards of H and Br, the app will display the molecular model of HBr). The instructor may allow students to choose different elements’ cards to form various different molecular models in accordance to the needs of the course. Students may then observe the different ways molecular models can be displayed (e.g. molecular model, Lewis electron models, ball-and-stick model, Van der Waals radius model etc.). This app utilizes emerging technology to enhance students’ learning motivation, provides students with ways to get to know about the structure and representation of materials, and enables the formation of the correct conceptual understanding on material structure through discussions amongst students.

Polarity of water

The third app’s aim is to introduce the concept of polarity between different compounds (such as H₂O, CH₂O, and CH₄). The chemical compounds were chosen purposefully. For example, one of the most valuable properties of water is its ability to dissolve many different ionic or polar substances. Water molecules as a solvent can cause favorable electrostatic interactions with the ionic and polar solute. The surrounding water molecules can form favorable solvation shell to compensate the excluded space of introducing the solute in water through inter-water hydrogen bond interactions. This polarity gives water a greater ability to dissolve compounds. Sanger and Badger (2001) indicated that students who received instructions with computer simulations of electron-density plots were more likely to explain that the intermolecular attractions among water molecules are responsible for the immiscibility of oil and water, and were also more likely to recognize that water molecules are attracted to sodium ions, chloride ions, and each other, but are not strongly attracted to hydrogen molecules.

Our design allows users to observe the structures of each individual compound with multiple representations, and more importantly, to observe how the “positive ends” of the polar compounds (such as water molecules) are attracted to the negatively charged anions to form hydrogen bonds, and that the “negative ends” of the polar compounds to the positively charged anions. This is called hydration in water molecules. Similar phenomena can be seen between ionic substances (such as water and formaldehyde) but not between polar and non-polar molecules (such as water and methane) or between non-polar molecules (such as among methane molecules) (See Figure 7).

Figure 7:

ARs for polar and nonpolar compounds and formation of hydrogen bonds.

Carbon nanotube

The interesting cylindrical shape of nanotubes are composed of carbon atoms linked in hexagonal shape. Carbon nanotubes have several characteristics (such as strength) that attract researchers and companies alike to invest in the research on its application potential. Figure 8 shows the three kinds of carbon nanotube structures, namely, armchair, zigzag, and chiral/helix. This app will show what they look like from a 3D perspective to help students visualize the spatial configuration of the structure. Teachers can ask students to identify the three types of carbon nanotube structures and explain why each type of structure holds different properties.

Figure 8:

Three kinds of carbon nanotubes.