The number of atoms in 0.008 g of phosphorus is:

$\left[\mathrm{P}=31\right]$

The number of atoms in $8$ g of iron is:

$\left[\mathrm{Fe}=56\right]$

Amongst $11.5$ g of sodium or $15$ g of calcium, the element which has more atoms is:

$\left[\mathrm{Ca}=40; \mathrm{Na}=23\right]$

Amongst $6.4 \mathrm{g}$ of sulphur and $9.3 \mathrm{g}$ phosphorus, the element which has more moles is:

[Atomic mass of $\mathrm{S}=32, \mathrm{P}=31$]

$1$ g of silicon contains $\mathrm{P}$ atoms. The number of atoms in $1$ g of calcium is:

$\left[\mathrm{Si}=29; \mathrm{Ca}=40\right]$