In the nucleus of $_{20}Ca^{40}$,there are:

Give the symbol of the following species:
$(i)$ Number of electrons,protons,and neutrons are $10, 8$,and $8$ respectively.
$(ii)$ $Ca$ $(Z = 20)$ and nucleon number $= 40$.
$(iii)$ Species with mass number $25$,protons $12$ (magnesium),and electrons $10$.
$(iv)$ Species of Bromine in which $(Z = 35)$,electrons $36$,and neutrons $45$.
$(v)$ $+2$ positive and $-2$ negative ions that are isoelectronic with $Al^{3+}$ $(Z = 13)$.

If the atomic weight of an element is $23$ times that of the lightest element and it has $11$ protons,then it contains

Which of the following is an isobaric pair?

Symbols $_{35}^{79} Br$ and $^{79} Br$ can be written,whereas symbols $_{79}^{35} Br$ and $^{35} Br$ are not acceptable. Answer briefly.

An element $_ZM^{19}$ has $10$ neutrons in its nucleus. To which block does it belong?