Question

What charge does calcium, $Ca,$ have when it becomes an ion?

Answer 1

Hint :Here to answer this question we should talk about electro neutrality. According to electro neutrality an amount of charge can be balanced by an equal amount of opposite charge. So, we will check the charge of both the ions. Then will determine how much one type of charge is required to balance the opposite charge.

Complete Step By Step Answer:
During the formation of cation the number of electrons gets decreased while the number of protons gets increased while during the formation of anion the number of electrons gets increased while the number of protons gets decreased. Number of electrons increased or decreased in an ion depends upon the addition and removal of electrons.
Higher the number of electrons gain higher will be negative charge on an anion and higher the number of electrons lost higher will be the positive charge on a cation. In an anion or cation, the numbers of neutrons are calculated by the help of the following formula in which the number of protons are required only because during the formation of cation or anion number of electrons get changed.
The formula of calcium ion is $C{a}^{2+}$ it means that the calcium atom loses two electrons and forms a calcium ion $C{a}^{2+}.$ $Ca,$ generally loses two electrons from its outer shell to form a $C{a}^{2+}$ ion.
Charge on $C{a}^{2+}$ ion is; where charge of electrons is $1.602\times {10}^{-19}$
 $q=2positivecharge\times {\displaystyle \frac{1.602\times {10}^{-19}}{protons}}=3.21\times {10}^{-19}C$

Note :
Note that the cations are mainly formed by metal of S-Block, D-Block and F-Block, and some metals of P-Block too, while anions are formed by non-metals. When an atom donates electrons some other atom takes electrons. The number of electrons transferred by a cation depends upon the number of electrons that will be taken by an anion.