Question

Weight of 50 atoms of an element is 3000 a.m.u. Calculate the number of atoms in 240 grams of element?

Answer 1

There are `2.41 × 10^24 color(white)(l)"atoms"`.

Explanation:

`"Mass of 1 atom" = 1 color(red)(cancel(color(black)("atom"))) × "3000 u"/(50 color(red)(cancel(color(black)("atoms")))) = "60.0 u"`

`"Mass of 1 mol of atoms = 60.0 g"`

`"Number of moles" = 240 color(red)(cancel(color(black)("g"))) × "1 mol"/(60.0 color(red)(cancel(color(black)("g")))) = "4.00 mol"`

`"Number of atoms" = 4.00 color(red)(cancel(color(black)("mol"))) × (6.022 × 10^23color(white)(l) "atoms")/(1 color(red)(cancel(color(black)("mol")))) = 2.41 × 10^24color(white)(l) "atoms"`