Calcium has 20 electrons
period 3 elements in the periodic table have 3 electrons in there outher shell hence the name.
Chlorine has 17 electrons. It is displayed as atomic number in periodic table.
Two valence electrons
For example the elements from the group 1 of the periodic table.
Depends on the element. Check out the "Periodic Table".
Usually calcium loses 2 electrons, that's why calcium is found in Group 2 of the periodic table.
its in column two on the periodic table, so therefor it has two valence electrons .
I believe it is 2, seeing it is a metal, and has 2 valence electrons. Correct me if I'm wrong, I don't have my periodic table with me (Calcium -> Ca?).
Calcium is in group II of the periodic table meaning that it has 2 valence electrons. These are the electrons that are involved in making a chemical bond, so the answer to your question is TWO.
I am not sure what you mean by atoms, i think you mean electrons (part of an atom).Calcium is in Group 2 of the periodic table so this means that in order to become stable it will lose 2 electrons.
Xenon has 54 electrons.
period 3 elements in the periodic table have 3 electrons in there outher shell hence the name.
By looking at the Periodic Table.
Chlorine has 17 electrons. It is displayed as atomic number in periodic table.
Two valence electrons
Just so you know, the periodic table does not give any indication of how many electrons an atom has but 95% of sulfur atoms are neutral and so contain 16 electrons.
2, as indicated by its position in periodic column 2.