For a neutral atom, the number of positive protons is equal to the number of negative electrons and the charge is zero.
For this question, we see that the number of protons exceeds the number of electrons by 2, which means that this ion in a positively charged charged ion with charge of +2.
Rubidium would exhibit the greatest shielding [ effect. ]
Answer:

Explanation:
The original calculation to find the number of moles which is
can be rearranged to give the equation
. Therefore the amount of molecules can be found by
(multiplying by Avogadro's Number)