Answer quickly, i don't understand how to do this properly. potassium forms ions with a charge of +1 (ka+). iodine forms ions with a charge of -1. selenium forms ions with a charge of -2 ( imagine that potassium ions and selenide ions combine to form potassium selenide. what numbers would be in the place of x and y in: kxsey (use the number 1 even if it isn't strictly necessary)

Answer :  2 and 1 are the numbers in the place of X and Y in .

Explanation :

Crisscross method : It is a method of finding a chemical formula in which ionic bond is formed by combining of metal and non-metal.

The charge on Potassium ion is +1 and the charge on Selenide ion is -2.

The potassium ions combined with the selenide ions to form a Potassium selenide. Image is also show below.

According to the crisscross method,

The formula of Potassium selenide is .

Therefore, 2 and 1 are the numbers in the place of X and Y in .

it is stable as it is in group 0 which have full outer shells of electrons