Question

How do you find the number of neutrons in an element on the periodic table?

Answer 1

Hint: To find the number of neutrons, you should first know about the number of protons present in an atom and then, subtract the number of proton from the atomic mass of that very element, you will get the number of neutrons of the atom. Now solve it.

Complete step by step answer:
First of all, let’s discuss what an atom is. An atom is the smallest particle of an element and consists of the electrons, protons and the neutrons. Atoms are the smallest particles of an element. An atom consists of a large number of particles i.e., electrons, protons and neutrons.
The center of the atom is occupied by a large solid mass which is known as the nucleus of the atom. The electrons revolve around the nucleus in fixed orbits.
The protons and neutrons are present inside the nucleus and the number of electrons present in an atom depends upon the number of protons present in the nucleus.
Now considering the statement as;
We can find the number of neutrons in an atom by using the formula as;
$Z+N=A$
Here, Z is the atomic number .
N represents the number of neutrons
A is the atomic mass of the atom.
Example: In nitrogen-15, an isotope of nitrogen, there are seven protons and mass number is 15. So, Z=7
And A=15
Then; the number of neutrons in the nitrogen-15 is eight.
$\begin{align}
& 7+N=15 \\
& N=15-7=8 \\
\end{align}$
Thus, we can find the number of neutrons in an element on the periodic table

Note: Protons are the positively charged particles of the atom, electrons are the negatively charged particles of the atom and neutrons are the neutral particles of the atom i.e., they do not carry any charge.