Radioactive uranium decays into lead what relative amount of uranium and lead would the reader expect to five in the oldest rocks

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

Why does his teacher ask him to balance the equation by including the correct coefficient

What is a possible quantum number set for an electron in the 3s orbital of a magnesium atom