What is the number of moles of oxygen atoms and the number of moles of $N$ atoms respectively present in one mole of thymine?

The ratio of masses of oxygen and nitrogen in a particular gaseous mixture is $1 : 4$. The ratio of the number of their molecules is:

Among the following,choose the ones with an equal number of atoms.
$A$. $212 \ g$ of $Na_2CO_3(s)$ [molar mass $= 106 \ g/mol$]
$B$. $248 \ g$ of $Na_2O(s)$ [molar mass $= 62 \ g/mol$]
$C$. $240 \ g$ of $NaOH(s)$ [molar mass $= 40 \ g/mol$]
$D$. $12 \ g$ of $H_2(g)$ [molar mass $= 2 \ g/mol$]
$E$. $220 \ g$ of $CO_2(g)$ [molar mass $= 44 \ g/mol$]
Choose the correct answer from the options given below.

In a sample of $CaCO_3$,there are $3.01 \times 10^{23}$ ions of $Ca^{+2}$ and an equal number of $CO_3^{-2}$ ions. The mass of the sample is = $......$ grams.

Which one of the following has the maximum number of atoms?

The highest number of helium atoms is in