Question

Identify the isotopes out of A , B , C and D ?

${}_{17}{}^{33}\mathrm{A}$, ${}_{20}{}^{40}\mathrm{B}$, ${}_{17}{}^{37}\mathrm{C}$, ${}_{19}{}^{38}\mathrm{D}$.

Answer 1

Isotopes:

Isotopes are the atoms of the same element having the same atomic number but different mass numbers.

For ${}_{17}{}^{33}\mathrm{A}$:

1. The atomic number is $17$.
2. The mass number is $33$.

For ${}_{20}{}^{40}\mathrm{B}$:

1. The atomic number is $20$.
2. The mass number is $40$.

For ${}_{17}{}^{37}\mathrm{C}$:

1. The atomic number is $17$.
2. The mass number is $37$.

For ${}_{19}{}^{38}\mathrm{D}$:

1. The atomic number is $19$.
2. The mass number is $38$.

Identify the isotopes:

1. Out of A, B, C and D, A and C have the same atomic numbers i.e. $17$.
2. While the mass numbers of A and C are different i.e. $33$ and $37$ respectively.
3. Thus, A and C are the isotopes.