Question

The magnitude of the charge of a single electron or a proton is $1.6\times {10}^{-19}C$.
What is the net charge of an object that has 20 electrons and 22 protons?

• A. $+3.2\times {10}^{-19}C$
• B. $-3.2\times {10}^{-19}C$
• C. $+1.6\times {10}^{-19}C$
• D. $-1.6\times {10}^{-19}C$

Answer 1

The correct option is A

$+3.2\times {10}^{-19}C$

Protons carry a positive charge. Hence, the charge of each proton will be $+1.6\times {10}^{-19}C$

Electrons carry a negative charge. Hence, the charge of each electron will be $-1.6\times {10}^{-19}C$

Now the net charge of any particle is the sum total of all charges present in the particle.
The net charge of the particle in this case will be the sum of charges of 22 protons and 20 electrons.
$=22\times (+1.6\times {10}^{-19}C)$$+20\times (-1.6\times {10}^{-19}C)$

= $(+3.2\times {10}^{-19}C)$