The valence shell of sodium has one electron.
This is a chemical element. You can find the how many electron in a single atom by using a periodic table.
The number of valence electrons in the atom.
six
if you mean how many are in it then there are 20
two
Two dots are shown in the electron dot diagram for calcium in group 2 and period 4 with 20 protons and 20 electrons.
The valence shell of sodium has one electron.
5
You don't. Calcium is not an electron, calcium is a element
This is a chemical element. You can find the how many electron in a single atom by using a periodic table.
The number of valence electrons in the atom.
six
six
six
six
if you mean how many are in it then there are 20