Which of the following is an isobaric pair?

The mass numbers of two elements $X$ and $Z$ are $52$ and $75$ respectively. $X$ contains $16.6 \%$ more neutrons compared to protons. $Z$ contains $27.3 \%$ more neutrons compared to protons. $X$ and $Z$ are respectively

$({}_{32}Ge^{76}, {}_{34}Se^{76})$ and $({}_{14}Si^{30}, {}_{16}S^{32})$ are examples of

The number of electrons,protons and neutrons in a species are equal to $18$,$16$ and $16$ respectively. Assign the proper symbol to the species.

The number of electrons in $[_{19}^{40}K]^{-1}$ is

Which of the following has the maximum number of neutrons?