It's elementary... or is it?

Factual Questions
1

Whilst in my Chemistry class last week I noticed something strange.

There was a periodic table against the wall, and it had the noble gases to the far left, as opposed to being on the right where I was accustomed to seeing them. But that wasn’t all. At the top of this column was the following information (it was organised better in its original format):

[sub]0[/sub][sup]1[/sup]n: neutron. Mass: 1.008

Unfortunately, this table has been removed and replaced with a more up to date table.

Do neutrons count as atoms? If so, then why don’t more periodic tables include them? Where did the idea that resulted in this table come about?

-ryoushi

2

Never saw anything like it.

Neutrons, along with protons and electrons, are *components * of atoms.

Beats me.

3

Neutrons aren’t atoms, but I could see a chart giving the atomic weights of neutrons and protons just as a reference.

4

Neutrons, protons, and electrons are indeed components of atoms, but a free proton is itself an atom. It’s ionized Hydrogen-1. I can’t think of any reason why a neutron (or bunch of neutrons) would not be considered an atom of atomic number 0, but, officially, they’re not.

5

As for the position of the noble gases, you could argue that their reactivity (or lack of) is due to an empty shell (eg 1s[sup]2[/sup] 2s[sup]0[/sup] in helium rather than having complete shells (ie the 1s) so calling them ‘group zero’ rather than group eight is arbitrary IMO.

6

There is something ascetically pleasing about a neutron being called an atom with atomic weight zero. But, for any other element, if you have a neutron in the nucleus, you can remove it and you still have an isotope of the same element. If you take a neutron away from an atom of Zeronium[sup]1[/sup], wouldn’t that mean empty space is full of Zeronium[sup]0[/sup]?

7

I meant atomic number zero.