Is this true Bc I’m not sure

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 is the number of moles of chemical units represented by 9.03x10^24? and how do i show work? (dumb it down )

What is the percentage composition of carbon in the compound ch4