I do not want to know the answer, please just explain the steps (: I really appreciate it! This is a chem question

Agas mixture with a total pressure of 745 mmhg contains each of the following gases at the indicated partial pressures: co2, 245 mmhg ; ar, 119 mmhg ; and o2, 163 mmhg . the mixture also contains helium gas. part a what is the partial pressure of the helium gas? phe p h e = nothing mmhg request answer part b what mass of helium gas is present in a 10.2-l sample of this mixture at 283 k ? m m = nothing g request answer

What’s the scientific notation for the number 6,840,000,000

What is the mass defect of a mole of nuclei with 1.8 x 10^15 j/mol binding energy?