What part of the atom contains the protons and neutrons?

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

When water dissociates, each water molecule splits into a hydroxide ion and a) h 3 o + b) a hydrogen atom c) a hydrogen ion d) h 2 o e) oh —

Which of the following units is not an official si unit