Answer: 6.3 x 10^-3 moles
Explanation:
Based on Avogadro's law:
1 mole of any substance has 6.02 x 10^23 atoms
So, 1 mole of potassium = 6.02 x 10^23 atoms
Z moles = 3.78 x 10^21 atoms
To get the value of Z, we cross multiply:
(3.78 x 10^21 atoms x 1mole) = (6.02 x 10^23 atoms x Z moles)
3.78 x 10^21 = (6.02 x 10^23 x Z)
Z = (3.78 x 10^21) ➗ (6.02 x 10^23)
Z = 0.63 x 10^-2)
Place the result in standard form
Hence, Z = 6.3 x 10^-3 moles
Thus, there are 6.3 x 10^-3 moles of potassium in 3.78 x 10^21 atoms of K.
