What is responsible for the vivid colors of many minerals and
gemstones?

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

Afuel has 30.43% nitrogen and 69.57% oxygen. find the molecular formula of the compound if it has a mass of 92 grams per mole a.no b.n2o4 c.no2 d.n4o8

How does changing the surface area increase the reaction rate of a chemical change