what is an electron shell

In chemistry and atomic physics, an electron shell may be thought of as an orbit followed by electrons around an atom's nucleus. The closest shell to the nucleus is called the "1 shell", followed by the "2 shell", then the "3 shell", and so on farther and farther from the nucleus.

Explanation:

An electron shell is the outside part of an atom around the atomic nucleus. It is a group of atomic orbitals with the same value of the principal quantum number n

Explanation:

conduction, convection, radiation