Throughout the metallic structure allowing the atoms to slide past each other. This sliding is why metals are ductile and malleable. Ioniccompound must break bonds to slide past one another, which causes the ionic material to split and crack.
Epsom salt is a compound.
Atomic mass of helium is 4.002642g/mol
(542000g)/(4.002642g/mol)*6.02*10^23 = 8.15*10^28 atoms
