What does an atomic number represent atom? 20 pionts to who ever answers pls a)number of protons b)number of electrons c)number of neutrons d)number of protons and neutrons

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?

Two things that biomedical has invented or innovated

Which element forms an ionic bond with flourine? 1) fluorine 2) carbon 3) potassium 4) oxygen