The chlorine atom differs from the chloride ion in the number of:

An electrically charged atom or a group of atoms is known as

Match the isotopes in List $I$ with the number of neutrons in List $II$.

$(A)$. $^{24}_{12}Mg$	$(I)$. $5$
$(B)$. $^{27}_{13}Al$	$(II)$. $12$
$(C)$. $^{9}_{4}Be$	$(III)$. $6$
$(D)$. $^{12}_{6}C$	$(IV)$. $14$

The number of protons,neutrons,and electrons in the element $_{89}X^{231}$ are respectively:

Give the relation between the following pairs of species:
$(i)$ $_{20}^{40}Ca$ and $_{19}^{40}K$
$(ii)$ $_{17}^{35}Cl$ and $_{17}^{37}Cl$
$(iii)$ $_{18}^{40}Ar$,$_{20}^{40}Ca$ and $_{19}^{40}K$
$(iv)$ $_{38}^{87}Sr$ and $_{38}^{90}Sr$

Which of the following species does not have the same number of electrons as the other three species?