Question

${}_{14}{}^{28}\mathrm{Si}$ and ${}_{14}{}^{29}\mathrm{Si}$ are called ___________.

Answer 1

Isotopes

• Isotopes are the atoms of the same element having the same atomic number but different mass numbers.
• The isotopes differ in mass number because of the carrying number of neutrons in them.

${}_{14}{}^{28}\mathrm{Si}$ and ${}_{14}{}^{29}\mathrm{Si}$:

• Here silicon has the same atomic number of $14$ and variable mass numbers of $28$ and $29$.
• Therefore ${}_{14}{}^{28}\mathrm{Si}$ and ${}_{14}{}^{29}\mathrm{Si}$are two isotopes of silicon.
• ${}_{14}{}^{28}\mathrm{Si}$ has $14$neutrons.
• ${}_{14}{}^{29}\mathrm{Si}$ has $15$neutrons.

Hence, ${}_{14}{}^{28}\mathrm{Si}$ and ${}_{14}{}^{29}\mathrm{Si}$are called Isotopes.