It is 4 because if you think about it it makes more sense
Its chemical formula H2O, indicates that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds. The hydrogen atoms are attached to the oxygen atom at an angle of 104.45°. "Water" is the name of the liquid state of H2O at standard conditions for temperature and pressure.
Answer:
the work done on the gas is 4,988.7 J.
Explanation:
Given;
number of moles of the monoatomic gas, n = 4 moles
initial temperature of the gas, T₁ = 300 K
final temperature of the gas, T₂ = 400 K
The work done on the gas is calculated as;

For monoatomic ideal gas: 

Where;
R is ideal gas constant = 8.3145 J/K.mol

Therefore, the work done on the gas is 4,988.7 J.
For a mole of P4O10, there are 4 moles of P. Hence for 76 moles of P4O10, the number of P moles is a total of 304.