On the periodic table, there are two numbers in the block for the element potassium, k: 19 and 39.098. what are the names of the numbers and what do they measure?

It represents as 19 K 39.098

Here, 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...

force required to detach it is given by

charges are taken to be fundamental charge

now we have

so above is the minimum distance at which it will detach