A force is a push or pull on an object that could affect its motion. Which is an example of a non-contact force?

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?

What are transitions between a liquid and a solid called? identify which way they are transitioning

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation: