Large objects that form dense gravity wells in space A. Galaxies B. Star C. Nebulae D. Black holes.​

Asample of the male sex hormone testosterone, c19h28o2, contains 3.88×10^21 atoms of hydrogen.(a) how many atoms of carbon does it contain? (b) how many molecules of testosterone does it contain? (c) how many moles of testosterone does it contain? (d) what is the mass of this sample in grams?

In which reaction is precipitation occurring?

Why is retrograde motion an apparent motion