An Ideal Gas Composed of Helium Atoms Is at a Pressure

Multiple Choice

An ideal gas composed of helium atoms is at a pressure of 2.00 atmospheres and a temperature of $35.0^{\circ} \mathrm{C}$ . What is the mass density? $(\mathrm{He}=4.00 \mathrm{u})$

A) $0.276 \mathrm{~kg} / \mathrm{m}^{3}$
B) $0.534 \mathrm{~kg} / \mathrm{m}^{3}$
C) $0.488 \mathrm{~kg} / \mathrm{m}^{3}$
D) $0.316 \mathrm{~kg} / \mathrm{m}^{3}$
E) $0.400 \mathrm{~kg} / \mathrm{m}^{3}$