How can a science student make a good prediction about what will happen in an investigation that has not been done yet? A. She can look at what happened in the past. B. She can think about what she wants to happen. C. She can make a wild guess. D. There is no way to make a good prediction

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?

Which of the following is true about the products formed during photosynthesis? (5 points) select one: a. they have the same mass as the mass of reactants. b. they are the same set of compounds as the reactants. c. they have more mass than the mass of reactants. d. they are chemically the same as the reactants.

An unknown substance is a white solid at room temperature and has a melting point of 78 °c. which of the following substances is most likely to be the identity of the unknown sample?