i would like to know why oxygen is a fairly reactive element but neon is not?

Answer 1

This has to do with electrons. Neon has a "full shell" of electrons, all of the inert gases do. Neon doesn’t want any electrons, and it doesn’t want to give them away. Oxygen wants "to look like" Neon. Oxygen has 6 electrons sitting in what is known as the outer shell, if oxygen gets to 8 like Neon it will be happy, to put it simply. This is also why Sodium is very reactive. Na will give away 1 electron so that it also looks like Neon. S wants to look like its counterpart Argon, Se wants to look like Kr.

Looking at the periodic table is really useful when learning how elements behave.

[edit] -the person below me just regurgitated something about protons and said my answer is invalid, and I'm a chemist so... Yes elements are defined by their number of protons, but these protons, being positive, attract electrons. Neon will attract 10 total electrons, the first two fill what is called the 1s orbital, next two fill the 2s, and the next six pair up into groups of two and fill the 3 lobes of the 2p orbital. Everything fills, no room for more electrons, no extra ones hanging out in too high of an orbital. Neon will not react because it will not take on more electrons and it will not lose them.

Answer 2

Look at a periodic table. Oxygen doesn't have a full complement of electrons in its outer shell, so it is always trying to get more electrons. This is what makes it reactive (the need for electrons).
Neon has a full set of electrons filling its outer shell and is perfectly content to stay the way it is. It doesn't need anything to make it more stable than it already is (why it is unreactive).

Answer 3

Interesting question... Don't think much of the answers so far. An element is defined by the number of protons, not electrons... Adding, or subtracting electrons ionizes the element, it doesn't change it to another element.

Answer 4

look at the periodic table, and the answer will be clear