Answer:
Electrons In The Shells
Take a look at the picture below. Each of those colored balls is an electron. In an atom, the electrons spin around the center, also called the nucleus. The electrons like to be in separate shells/orbitals. Shell number one can only hold 2 electrons, shell two can hold 8, and for the first eighteen elements shell three can hold a maximum of eight electrons.As you learn about elements with more than eighteen electrons you will find that shell three can hold more than eight. Once one shell is full, the next electron that is added has to move to the next shell.
So... for the element of CHLORINE, you already know that the atomic number tells you the number of electrons. That means there are 17 electrons in a chlorine atom. Looking at the picture, you can see there are two electrons in shell one, eight in shell two, and seven in shell three.
