This activity uses the excellent AZER atom model to depict ionic bonding of sodium and chloride forming table salt. It should be part of instruction on chemical bonding and the use of other examples of chemical bonding could also be used.
electron – a negatively charge subatomic particle with very little mass
neutron – a subatomic particle with no charge located in the nucleus of an atom
proton – a subatomic particle with a positive charge located in the nucleus of an atom
electron cloud – an area around the nucleus of an atom where electrons are likely to be found
valence electron – an electron that is found in an atom’s outermost energy level and that determines the atom’s chemical properties.
chemical bond – an interaction that holds atoms or ions together
ionic bond – chemical bonding which occurs when valence electrons are transferred between atoms
covalent bond – chemical bonding which occurs when valence electrons are shared among atoms
This item is also part of the APH AZER Periodic Table Study Set.
Prepare one AZER atom as a sodium atom (Na) – As shown.
Prepare one AZER atom as a chlorine atom (Cl) As shown.
This activity should be appropriate after the structure of the atom has been covered thoroughly and valence electrons introduced.
Students should also have been introduced to the APH Azer model prior to this activity and should understand the varying sizes and tactile surfaces used for 1,5 and 10 neutrons or protons. See instructions to the model.
Pass out a Cl atom to one student and a Na atom to a second student.
Remind students of recent discussion of bonding and valence electrons and discuss.
Have students look at their atoms and their neighbors atoms. As shown. Ask – Which electrons in the atom are closest to the electrons of your neighbors atom? Discuss valence electrons and bonding. The electrons closes to the other atom are those which affect bonding – e.g. the electrons on the outer electron level or valence electrons.
Have students determine the number of valence electrons of the atom which he/she was given and then have students switch with their neighbor.
Determine the number of valence electrons again.
Remind students that the 2nd and 3rd levels of electrons are full with 8 electrons.
Ask students whether either of the atoms has 8 electrons in the outer level. Students should notice that neither does and that Na has only 1 and that Cl has 7.
Ask – Will it be easier for Na to give up 1 or gain 7 to have a full outer layer? Students should respond that it will be easier to give up one.
Ask – Will it be easier for Cl to give up 7 or gain 1 in order to have a full outer layer? Students should respond that it will be easier to gain one.
Have the students with Cl “steal” one electron from the outer level of the Na atom. As shown.
Again ask students whether the outer electron level in each atom is full. Yes
Discuss ionic bonding in more detail after the activity Ionic bonding of atoms occurs when one atom effectively “steals” one or more electrons from another atom to become more stable.
The activity is described for 2 students but can be adapted for one by having the instructor play the “neighbor” as per the the procedure.
High School Physical Science PS1.A: Structure and Properties of Matter
Each atom has a charged substructure consisting of a nucleus, which is made of protons and neutrons, surrounded by electrons. (HS-PS1-1)
The structure and interactions of matter at the bulk scale are determined by electrical forces within and between atoms. (HS-PS1-3),(secondary to HS-PS2-6)
PS2.B: Types of Interactions
Attraction and repulsion between electric charges at the atomic scale explain the structure, properties, and transformations of matter, as well as the contact forces between material objects. (secondary to HS-PS1- 1), (secondary to HS-PS1-3), (HS-PS2-6)