An atomic model shows 19 protons, 20 neutrons, and 19 electrons. What is the mass number of the atom?

Two liquids are shaken together in a test tube to produce a mixture that quickly separates into two layers. which of the following best describes the behavior of the above pair of substances? soluble insoluble miscible immiscible

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?

Type the letter that represents the correct location for each particle type below.