Question

Which of the following statements is wrong about isotopes?

• A. Isotopes have same number of electrons
• B. Isotopes have same chemical properties
• C. Isotopes have same number of neutrons
• D. Isotopes have same number of protons

Answer 1

The correct option is C Isotopes have same number of neutrons

Statement $C$ is incorrect.
Isotopes have the same atomic number but a different mass number. They have the same number of electrons and the same number of protons but the different number of neutrons.

For example, two isotopes of $chlorine$ are $C{l}_{17}^{35}$ and $C{l}_{17}^{37}$. They have 17 electrons and 17 protons each. $C{l}_{17}^{35}$ has 18 neutrons and $C{l}_{17}^{37}$ has 20 neutrons.

Isotopes have the same chemical properties as they have the same number of electrons.