When an atom's outer energy levels are not filled completely, the atom a. cannot form a compound b. is a noble gas c. can gain, lose, or share electrons d. is very stable

c. can gain, lose, or share electrons

Explanation:

The goal of every atom is to have a complete electronic configuration. But what does that mean?

It means atoms would react when they want to completely fill their atom's energy levels. This explains why noble gases rarely undergo reactions.

Option A is wrong because, when the atom's outer energy levels are not filled completely, the atom reacts to form a compound.

Option B is wrong because the noble gases are the atoms in which their outer energy levels is completely filled.

Option C is correct because depending on the number of valence electrons (outermost electrons)  an atom, can eitther gain (especially group 5,6 and 7), lose (groups 1,2 and 3) or share electrons (mainly group 4).

Option D is wrong because only the noble gases are stable.

can you list the answers so i can answer

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.