8
There is a total of 8 electrons that are needed to fill outer shell of most atoms. An atom is the smallest unit of matter.
8 electrons on the outer shell
The outer shell of an atom is the valence shell, which contains the valence electrons.
"valance shell"
Electrons in the outer most shell are called Valence Electrons.
No atom can hold 18 electrons in its outer energy shell - there is the valence rule, stating that the maximum for the outer shell is 8 electrons.
Valence Electrons
An oxygen atom has six (6) electrons in its outer shell.
A chloride anion contains eight outer shell electrons, one more than the seven outer shell electrons found in a chlorine atom.
valence electrons are the electrons located in the outer shell of an atom which are available for reaction
Electrons per shell in astatine: 2, 8, 18, 32, 18, 7.
The outer valence shell of a sulfur atom contains a total of 6 electrons: two 3s electrons and four 3p electrons.