Sylvanite is a mineral that contains 28.0% gold by mass. how much sylvanite would you need to dig up to obtain 44.0g of gold?

Embryos of different species look very similar, which shows that the organisms share a ancestor.

Which statement can best be concluded from the ideal gas law?

Sodium sulfate dissolves as follows: na2so4(s) → 2na+(aq) + so42- (aq). how many moles of na2so4 are required to make 1.0 l of solution in which the na concentration is 0.10 m?