Answer to Question #128264 in General Chemistry for ansley

Question

Calculate the number of atoms in a 7.84×103 g sample of cesium.

Answer 1

1 mole of any compound contains 6.022 * 10²³ atoms.

1 mole of cesium weighs 133 g.

Find how many moles of cesium do we have:

$\nu$ (Cs) = 7.84 * 10^3 / 133 = 58.95 (mol)

Find how many atoms of cesium do we have:

N(Cs) = 58.95 * 6.022 * 10²³ = 3.55 * 10²⁵ (atoms)

Answer: there are 3.55 * 10²⁵ atoms in a 7.84×103 g sample of cesium.