Question

When are atoms considered stable?

when they have satisfied the law of conservation of mass naturally or through bonding to obtain
full valence shells

when they have satisfied the octet rule naturally or through bonding to obtain full valence shells

when their valence electrons have "fallen" back to ground state through bonding

Answer 1

Atoms are considered stable when they satisfy the octet rule by having eight electrons in their valence shell, except for hydrogen and helium. They achieve this stability through bonding, where atoms give up, gain, or share electrons to fill their valence shells. An example of this is the water molecule, H₂O.

Step-by-step explanation:

All atoms (except hydrogen and helium with their single electron shells) are most stable when there are exactly eight electrons in their valence shell. This principle is referred to as the octet rule, and it states that an atom will give up, gain, or share electrons with another atom so that it ends up with eight electrons in its own valence shell. For example, oxygen, with six electrons in its valence shell, is likely to react with other atoms in a way that results in the addition of two electrons to oxygen's valence shell, bringing the number to eight. When two hydrogen atoms each share their single electron with oxygen, covalent bonds are formed, resulting in a molecule of water, H₂O.