Answer: Option (a) is the correct answer.
Explanation:
Atomic number means the sum of total number of protons acquired by an atom.
So, when atomic number of nitrogen is 7 then it means there are 7 protons present.
Whereas atomic mass means the sum of total number of protons and neutrons present in an atom.
Therefore, nitrogen-15 is an isotope of nitrogen that will always have 7 protons when it is neutral in nature. Hence, in nitrogen-15 the number of protons and neutrons are calculated as follows.
Atomic mass = no. of protons + no. of neutrons
15 = 7 + no. of neutrons
no. of neutrons = 15 - 7
= 8
Thus, we can conclude that the atomic nucleus of nitrogen-15 contains 8 neutrons.
Atomic number is the number of protons in an element. Mass number is the total number of protons and neutrons in an element. Thus, to get the number of neutrons in an element, one can subtract the atomic number of an element from the mass number.
Since Nitrogen has an atomic number of 7, the number of neutrons in nitrogen with a mass number of 14 is 14 - 7 = 7 neutrons
The number of neutrons in nitrogen with a mass number of 15 is 15 -7 = 8 neutrons
Thus, the answer to the question is 8 neutrons.
Note: Nitrogen-14 means nitrogen with a mass number of 14 while nitrogen-15 means nitrogen with a mass number of 15
