Question

Question: How are ionic compounds formed?


Observe: Look at the red lithium atom and the blue oxygen atom. Recall that most atoms are stable when their outermost ring has eight electrons. (Some atoms, such as lithium and beryllium, are stable when their outermost ring has two electrons.)

A. How many electrons will the lithium atom give up to become stable?



B. How many electrons does the oxygen atom need to become stable?



C. Can a stable compound be made from these two atoms? Explain why or why not.

Answer 1

A—— 1electron
B——— it requires 2 electrons
C—— a stable compound cannot be made since, when they form a compound the sharing of electrons will not happen since oxygen requires 2 electrons but lithium has only one therefore a stable atom can be formed

Answer 2

Ionic compounds consists of positive and negative ions to form a neutral compound.

A. Lithium atom gives 1 electron to become stable.

B. Oxygen atom needs 2 electrons to become stable.

C. No, a stable compound cannot be formed from only these two atoms.

Explanation:

• Ionic compound consists of an equal number of cations(positive ions) and anions(negative ions) which are held together by electrostatic forces to form neutral compounds.
• For an atom to remain more stable, its outer orbit must be complete. Lithium atom consists of 3 electrons with one electron in its outer orbit.
• So Lithium needs to lose its extra electron on the outer most orbit to become stable and in this process Lithium becomes a positive ion $(Li^{+1})$.
• Oxygen atom consists of 8 electrons with 6 electrons in its outer orbit. So it requires 2 more electrons to become stable. Hence it gains 2 electrons and forms a negative ion $(O^{-2} )$.
• A stable compound consists of equal charges in both cations and anions. Since lithium atom and oxygen atom has different charges it is not possible to form a stable compound with only 2 atoms.