Please help on question 7 and 8

At a temperature of 393 k, the temperature of a sample of nitrogen is 1.07 atm what will the pressure be at a temperature of 478 k

Ican determine the molar mass of an element by looking on the under the atomic mass for the element. for example the molar mass of phosphorus is 30.974 grams/mole. avogadro’s number tells me the amount of representative particles in 1 mole of any substance. this means 12.011 gram sample of carbon and a 32.0 gram sample of sulfur have the same number of atoms.

What is the subscript for oxygen in its molecular formula