What is the molar mass of al2(so4)3?
150.03 g/mol
278.03 g/mol
342.17 g/mol
450.09 g/mol

1) we find  out the atomic mass of these elements (Al, S, O)Atomic mass (Al)=27 amuAtomic mass (S)=32 amuAtomic mass (O)=16 amu2)Now, we calculate the molar mass of Al₂(SO₄)₃molar mass=2(27)+3[32+4(16)]=54+3(32+64)=54+3(96)=54+288=342 g/mol. 342.17 g/mol.

since the atomic number is the number of protons in the nucleus, as we move to the left on the periodic table, the electrostatic pull between the nucleus and the valence electron shell decreases. as we move down a group (vertical column), the valence shell energy level gets further and further from the nucleus.