The phosphide ion has an electronic structure similar to that of:

List the isotopes of hydrogen,carbon,and chlorine,and specify the number of protons,electrons,and neutrons for each.

Elements $A$ and $B$ have the same mass number. Their atomic numbers are $27$ and $30$ respectively. If the mass number of $A$ is $57$,find the number of neutrons in $B$.

An atom has a mass number of $25$ and contains $13$ neutrons in its nucleus. What is the charge of its ion if it forms a stable octet?

Which of the following is not true in Rutherford’s nuclear model of atom?

An element has an atomic weight of $40$ and its electronic configuration is $1s^2 2s^2 2p^6 3s^2 3p^6$. What are its atomic number and the number of neutrons?