An isobar of ${ }_{20} Ca^{40}$ is

Write the complete symbol for the atom with the given atomic number $(Z)$ and atomic mass $(A)$:
$(i)$ $\quad Z=17, A=35$
$(ii)$ $\quad Z=92, A=233$
$(iii)$ $\quad Z=4, A=9$

If $W$ is the mass number and $N$ is the atomic number of an element,then:

Which of the following is an isobaric pair?

Which of the following has the maximum number of neutrons?

$A$ sodium cation $(Na^{+})$ has a different number of electrons from: