Calculate the number of atoms in a 7.91×103 g sample of calcium.

Which of these conditions most likely produces an unstable isotope?

How many grams of oxygen gas are contained in a 15 l sample at 1.02 atm and 28°c? show your work.

Insoluble sulfide compounds are generally black in color. which of the following combinations could yield a black precipitate? check all that apply. na2s(aq)+kcl(aq) li2s(aq)+pb(no3)2(aq) pb(clo3)2(aq)+nano3(aq) agno3(aq)+kcl(aq) k2s(aq)+sn(no3)4(aq)