Which of the following contains the greatest number of atoms?

The number of moles of water present in a spherical water droplet of radius $1.0 \ cm$ is,(Given: Density of water in the droplet $= 1.0 \ g \ cm^{-3}$)

Calculate the number of valence electrons in $4.2 \, g$ of $N^{3-}$ ions.

How many water molecules are there in one drop of water $($Volume $= 0.0018 \ mL)$ at room temperature?

$A$ thin layer of cobalt is deposited on a plate with a total area of $0.5 \ m^2$ and a thickness of $0.005 \ cm$. How many cobalt atoms are deposited on the plate? (Density of cobalt $= 8.9 \ g \ cm^{-3}$,Atomic mass of $Co = 59 \ g \ mol^{-1}$)

The number of molecules in $4.25 \ g$ of ammonia is approximately