Question

The charge of an electron is $- 1.6 \times {10^{ - 19}}$ coulombs. What will be the value of charge on $N{a^ + }$ ion?
A) $1.6 \times {10^{ - 19}}C$
B) $32 \times {10^{ - 19}}C$
C) $2.4 \times {10^{ - 19}}C$
D) $10 \times 1.6 \times {10^{ - 19}}C$

Answer 1

As we all know that electrons are the smallest subatomic particles carrying a negative charge of $- 1.6 \times {10^{ - 19}}$ coulombs. And we also know that when an electron is lost from an atom, it bears a positive charge and when the electron is gained, it bears a negative charge and the charge is the product of the number of electrons and charge on the electron.

Complete solution:
As we know that sodium contains a total of eleven electrons in its native atom, but when it loses one electron a positive charge is added to the atom suggesting that the sodium now contains only ten electrons and when a negative charge is added it means sodium has gained an electron and the total electrons now it has is twelve.
Now we know that charge of an electron is $- 1.6 \times {10^{ - 19}}$ coulombs and we also are aware with the formula to calculate the charge on any atom which can be given as:
$q = ne$
where $q$ is the charge, $n$ is the number of electrons and $e$ is the charge on the electron.
Now, we also know that sodium is neutral in its native state and has only one electron to lose, so we can also assume that the charge on $N{a^ + }$ can be:
$q = 1 \times 1.6 \times {10^{ - 19}}$

Therefore, from the above explanation we can say that the correct answer is (A).

Note: There is also another answer as we have already discussed the number of electrons in $N{a^ + }$is $11 - 1 = 10$. By putting this value in the above given formula we will get the charge on sodium ion and it will be: $q = 10 \times 1.6 \times {10^{ - 19}}$. Remember that the charge on the atom after losing or gaining of one electron or more than one electron will be used to calculate the charge on the ion by simply taking the product of the number of electrons and electronic charge.