We can find the number of moles of PH₃ using ideal gas law equation
PV = nRTwhere
P - standard pressure - 101 325 Pa
V - volume - 250 x 10⁻⁶ m³
n - number of moles
R - universal gas constant - 8.314 Jmol⁻¹K⁻¹
T - temperature - 273 K
substituting the values in the equation
101 325 Pa x 250 x 10⁻⁶ m³ = n x 8.314 Jmol⁻¹K⁻¹ x 273 K
n = 0.011 mol
therefore mass of PH₃ = 0.011 mol x 34 g/mol = 0.374 g
mass of PH₃ is 0.374 g
Mass = Density x Volume
Mass = 3.2g/mL x 5 mL
Mass = 16g
The answer is <span>D.when the aim is to show electron distributions in shells. This is because there are some instances when elements don't possess a regular or normal electron configuration. There are those who have special electron configurations wherein a lower subshell isn't completely filled before occupying a higher subshell. It is best to visualize such cases using the orbital notation.</span>
