What is the number of molecules present in $44 \ g$ of $CO_2$?

Which of the following has the maximum number of molecules?

The number of molecules and atoms present in $1.2 \ g$ of ozone $(O_3)$ are respectively:

$K-40$ is a natural radioactive isotope which constitutes $0.012\%$ of natural potassium. If a cup of milk contains $370 \ mg$ of $K$,how many atoms of $K-40$ are ingested?

If Avogadro number $N_A$ is changed from $6.022 \times 10^{23} \ mol^{-1}$ to $6.022 \times 10^{20} \ mol^{-1},$ this would change

The number of oxygen atoms in $4.4 \ g$ of $CO_2$ is approximately: