Question

There are _______ isotopes of chlorine
A. $0$
B. $1$
C. $2$
D. $3$

Answer 1

Hint: We must know that chlorine is one of the elements in the periodic table. It is present in the halogen group. In the periodic table, chlorine in the seventeenth group and second period. The symbol of chlorine is $Cl$ . As we know that the isotopes mean more than two atoms having the same atomic number but different mass number. An atomic number of the element is equal to the number of protons or number of electrons in that atom. The mass number of the element is equal to the sum number of protons and neutrons in that atom. Chlorine is the most electron affinity element in the periodic table.

Complete step by step answer:
We need to remember that in the chlorine atom, there are two stable isotopes. There are ${}_{17}C{l^{35}}$ and ${}_{17}C{l^{37}}$ . In ${}_{17}C{l^{35}}$ and ${}_{17}C{l^{37}}$ both are having same atomic number of $17$ but the mass number wise different one have $35$ and other have $37$ . That is the reason ${}_{17}C{l^{35}}$ and ${}_{17}C{l^{37}}$ are to consider as isotopes of chlorine.
According to the above discussion, we concluded there are $2$ isotopes of chlorine.

So, the correct answer is Option C.

Note: We must have to know that in ${}_{17}C{l^{35}}$, this isotope of chlorine have $17$ protons, $17$ electrons and $18$ neutrons. Hence, the atomic number is $17$ and the mass number is $35$ . In ${}_{17}C{l^{37}}$, this isotope of chlorine has $17$ protons, $17$ electrons and $20$ neutrons. Hence, the atomic number is $17$ and mass number is $37$ . In naturally, ${}_{17}C{l^{35}}$ is a major isotope of chlorine, present in $75.78\% $ and ${}_{17}C{l^{37}}$ is present only in $24.22\% $ . These kinds of the isotope nature of chlorine, the relative atomic mass is $35.453$ . The relative atomic mass of the element depends on the percentage of that isotope present in the nature and atomic mass of that isotope. Here, the relative atomic mass of the chlorine is depend on the atomic mass and percentage of ${}_{17}C{l^{35}}$ and ${}_{17}C{l^{37}}$ .