# A weather balloon is inflated to a volume of 2.2 x 10^3 L with 37.4 g of He. What is the density of He in g/L?

$\rho = \text{Mass"/"Volume}$
Here, $\rho = \frac{37.4 \cdot g}{2.2 \times {10}^{3} \cdot L}$ $=$ ??g*L^-1.
Doing the calculation like this gives an answer in $g \cdot {L}^{-} 1$ as required for a density.