Question

Which of the following contains more number of neutrons?

• A. $S^{32}$
• B. $N{a}^{23}$
• C. $F{e}^{58}$
• D. $C{a}^{40}$

Answer 1

The correct option is C $F{e}^{58}$

The number of protons and neutrons present in the following elements are:

Number of neutrons $=$ Mass number $-$ atomic number

1) Sulfur(S) - 16P + 16N ( 32 - mass number)

2) Sodium(Na) - 11P + 12N (23 - mass number)
3) Ferrum(Fe) - 26P + 32N (58 - mass number)
4) Calcium(Ca) - 20P + 20N (40 - mass number)

Hence, the number of neutrons is maximum in $Fe$.