On the periodic table, there are two numbers in the block for the element potassium, k: 19 and 39.09. what are the names of the numbers and what do they measure?

 hy there the answer for this isIt represents as 19 K 39.098

the upper number which is 19, is atomic number, which means number of protons or number of electrons in non-ion phase.

And, lower number which is 39.098, is mass number, which means the sum of atomic number & number of neutrons...

Solubility would be your answer.