A shell surrounding the nucleus of an atom containing electrons.
The number of shells varies. The row number of the element is the number of shells. They don't really have names, but they're referred to by how many levels they are away from the nucleus.
Life on Earth is carbon based, so all animals with skeletons and shells use carbon. A more 'common' element used in skeletons and shells is calcium.
electronic chips with carbon in them.....
A subshell is a subdivision of electron shells.
Shells, Bones, and Teeth