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 less stable than a neon atom. an oxygen atom will increase its electron count by to fill its valence shell.

Explanation:

Step1: Analyze electron - shell of neon

Neon (Ne) has an atomic number of 10. Its electron - configuration is 2, 8. It has a full valence shell with 8 electrons, making it stable.

Step2: Analyze electron - shell of oxygen

Oxygen (O) has an atomic number of 8. Its electron - configuration is 2, 6. It has 6 valence electrons.

Step3: Determine how oxygen fills its valence shell

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

Answer:

2