Question

How many atoms are in 3.50 moles of calcium (Ca)?

Answer 1

$1\ mole\ --\ 6.02*10^{23}atoms\\ 3.5\ moles--x\\ x=21.07*10^{23}\ atoms$

Answer 2

No. of atoms = no.of moles x avagadro's constant

= 3.50 x 6.022*10^23

= 21.077 x 10 ^23