Question

One radioactive isotope of calcium has an atomic mass number of 47. How many neutrons are in the calcium-47 nucleus?

Answer 1

isotope means having the same number of protons but different number of neutrons.
Thus, by looking at the periodic table the prton number is 20.
no. of neutrons in the isotope of Ca=47-20
Therefore the number of neutrons in calcium-47 is 27 neutrons.

Answer 2

Answer: The number of neutrons in the given isotope are 27.

Explanation:

Atomic number is defined as the number of electrons or number of protons that are present in a neutral atom. It is represented as Z.

Z = Atomic number = Number of electrons = Number of protons

Mass number is defined as the sum of number of protons and number of neutrons present in an atom. It is represented as A.

A = Mass number = Number of protons + Number of neutrons

Number of neutrons = Mass number - Atomic number

We are given an isotope having representation:  $_{20}^{47}\textrm{Ca}$

Atomic number or number of protons = 20

Mass number = 47

So, number of neutrons = 47 - 20 = 27

Hence, the number of neutrons in the given isotope are 27.