# How many liters of helium gas are there in 0.003 L of He at STP?

I presume you want to know the molar quantity of $3 \times {10}^{-} 3 \cdot L$ at $\text{STP}$.
It is well known that at $\text{STP}$ $1$ $m o l$ of Ideal Gas will occupy a volume of $22.4 \cdot L$. (This will even be given as supplementary material in most examinations)
Thus $\text{Moles of helium}$ $=$ $\frac{3 \times {10}^{-} 3 \cdot \cancel{L}}{22.4 \cdot \cancel{L} \cdot m o {l}^{-} 1}$ $=$ ??*mol