How many grams of sodium contain the same number of atoms as 15.9 g of potassium?

Answer 1

First we find out how many MOLES of potassium are in 15.9 g of potassium. Then we use that number of moles of potassium as the number of moles of sodium and convert that to grams of sodium. We do this because 1 mole of ANYTHING has the same number of atoms/particles/etc as anything else.

15.9 g K x 1 mol K / 39.1 g = 0.4066 moles K

0.4066 mols Na x 22.99 g / mol = 9.35 g Na (3 sig. figs.)

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Both will have 0.4066 mol x 6.022x10²³ atoms/mol = 2.45x10²³ atoms