List four types of substances that may be found in natural water supplies​

**40** points asapessay questions (10 points possible) clear image of next, create your own scenario. it can be one of your own real experiences or one you make up. use imagery in your writing to give your instructor a the setting and an action taking pace in your writing explain the structure and functions of the skin at work in your scenario. !

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?

Choose all the answers that apply. fluorine (f) has an atomic number of 9 and an atomic weight of 18.99. fluorine has a. 9 protons b. 10 neutrons c. 18 electrons d. an atomic mass of 19 e. at least one isotope