1. The problem statement, all variables and given/known data How many anions are there in 1.50 g of MgBr2 2. Relevant equations 3. The attempt at a solution 1.5 g MgBr2 x (1 mol MgBR2/184.3 g MgBr2) x (6.022 x 1023 anions/mol) which gave me answer of 4.91 x 1021 the correct answer is 9.81 x 1021 am i missing a step, or do i have to create a balanced equations? and use a mol to mol ratio? any help is greatly appreciated.