Question

The atomic number of nitrogen is 7. How many protons, neutrons and electrons make up an atom of nitrogen-15?

Answer 1

Hint The number of protons in an atom is always equal to its atomic number i.e. Z and the number of electrons in an atom is always equal to the number of protons to maintain the electrical neutrality of the atom and we can find the number of neutrons by applying the formula as: $Z+N=A$. Now you can easily answer the given statement accordingly.

Complete step by step answer:
The Nitrogen-15 is an isotope of the nitrogen atom and is formed when the nitrogen atom gains one neutron in the nucleus. Isotopes are the substances which have the same atomic number but different mass number. So, in nitrogen-15, the atomic number of nitrogen is 7 and mass number of nitrogen is 15.
The number of protons in an atom is equal to the atomic number i.e., Z. And we know that the atomic number of nitrogen is 7, so, the number of protons in nitrogen is 7.
The number of electrons in an atom is always equal to the number of protons. So, in nitrogen-15, the number of protons in the nucleus are seven and thus, the number of electrons revolving around the nucleus is also seven.
The number of neutrons in an atom can be calculated as;
$Z+N=A$
Here, Z is the atomic number .
N represents the number of neutrons
A is the atomic mass of the atom.
As we know that;
Z=7
And A=15 (given)
Then;
$\begin{array}{rl}& 7+N=15\\ & N=15-7=8\end{array}$
So, the number of neutrons in the nitrogen atom is eight.

Hence, seven protons, eight neutrons and seven electrons make up an atom of nitrogen-15.

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.