Question

atoms tend to be stable when they have a full valence shell. most main - group elements require eight valence electrons to have a full valence shell. for this reason, atoms of most main - group elements will share, gain, or lose valence electrons until their valence shells contain eight electrons, or an octet. this observation is known as the octet rule. some atoms, like hydrogen and helium, do not obey the octet rule and are stable when they have two electrons in their valence shell. compare the bohr models of neon and oxygen. complete the sentences. an oxygen atom is than a neon atom. an oxygen atom will its electron count by to fill its valence shell.

Explanation:

Step1: Analyze atomic structure

Oxygen has 8 protons and neon has 10 protons. Smaller number of protons in oxygen means less positive - charge attraction for electrons, so oxygen is larger in size.

Step2: Determine valence - shell needs

Oxygen has 6 valence electrons. To have a full valence shell (8 electrons according to the octet rule), it needs to gain 2 electrons.

Answer:

An oxygen atom is larger than a neon atom. An oxygen atom will increase its electron count by 2 to fill its valence shell.