I got stood up by this guy
B R U H

As you move from right to left on the periodic table the atomic radius fill in the blank

Sodium sulfate dissolves as follows: na2so4(s) → 2na+(aq) + so42- (aq). how many moles of na2so4 are required to make 1.0 l of solution in which the na concentration is 0.10 m?

Which of the following is not true about the atomic model of substances?