Question

student exploration: ionic bonds
vocabulary: chemical family, ion, ionic bond, ionization energy, metal, nonmetal, octet rule, shell, valence electron
prior knowledge questions (do these before using the gizmo.)

1. nate and clara are drawing pictures with markers. there are 8 markers in a set. nate has 9 markers and clara has 7. what can nate and clara do so that each of them has a full set?
2. maggie is sitting at a table with fred and florence. maggie has 10 markers, but fred and florence each have only 7 markers. how can they share markers so each has 8?

gizmo warm - up
just like students sharing markers, atoms sometimes share or swap electrons. by doing this, atoms form bonds. the ionic bonds gizmo allows you to explore how ionic bonds form.
to begin, check that sodium (na) and chlorine (cl) are selected from the menus at right. click play (▶) to see electrons orbiting the nucleus of each atom. (note: these atom models are simplified and not meant to be realistic.)

1. each atom consists of a central nucleus and several shells that contain electrons. the outermost electrons are called valence electrons.

how many valence electrons does each atom have? sodium: ____ chlorine: ____

1. click pause (⏸). elements can be classified as metals and nonmetals. metals do not hold on to their valence electrons very tightly, while nonmetals hold their electrons tightly. ionization energy is a measure of how tightly the valence electrons are held.

a. try pulling a valence electron away from each atom. based on this experiment, which atom is a metal? ____________ which is a nonmetal? ____________
b. try moving an electron from the metal to the nonmetal. what happens? ______________

Explanation:

Step1: Analyze markers situation for Nate and Clara

Nate has 9 markers and Clara has 7. A full - set is 8 markers. Nate has 9 - 8=1 extra marker and Clara needs 8 - 7 = 1 marker. So Nate can give 1 marker to Clara.

Step2: Analyze markers situation for Maggie, Fred and Florence

Maggie has 10 markers, Fred has 7 and Florence has 7. The total number of markers is 10 + 7+7=24. If they want to have 8 markers each (since 24÷3 = 8), Maggie has 10 - 8 = 2 extra markers. She can give 1 marker to Fred and 1 marker to Florence.

Step3: Determine valence electrons of Sodium and Chlorine

Sodium (Na) has 11 electrons. Its electron - configuration is 2, 8, 1. So it has 1 valence electron. Chlorine (Cl) has 17 electrons. Its electron - configuration is 2, 8, 7. So it has 7 valence electrons.

Step4: Identify metal and non - metal based on ionization energy

Sodium is a metal as it has a low ionization energy and does not hold its valence electron tightly. Chlorine is a non - metal as it has a high ionization energy and holds its electrons tightly.

Step5: Analyze electron transfer from metal to non - metal

When an electron is moved from sodium (metal) to chlorine (non - metal), sodium becomes a positively charged ion (Na⁺) and chlorine becomes a negatively charged ion (Cl⁻). They are then attracted to each other and form an ionic bond.

Answer:

1. Nate can give 1 marker to Clara so that each has a full set.
2. Maggie can give 1 marker to Fred and 1 marker to Florence so that each has 8 markers.
3. Sodium: 1; Chlorine: 7
4. A. Metal: Sodium; Non - metal: Chlorine

B. Sodium becomes a positively charged ion (Na⁺) and chlorine becomes a negatively charged ion (Cl⁻), and they form an ionic bond.