The name would be aluminum nitrate. and the molar mass would be 213 because aluminum AMU (atomic mass unit) is 27 (26.98) plus NO3's AMU is 62 (62.004) and because there is 3 NO3's that is 186. 186 plus 27 is 213
To convert from moles to atoms, multiply the molar amount by Avogadro's number. To convert from atoms to moles, divide the atom amount by Avogadro's number (or multiply by its reciprocal).