If you add an electron does it become a positive charge

The following reaction shows sodium carbonate reacting with calcium hydroxide. na2co3 + ca(oh)2 → naoh + caco3 how many grams of naoh are produced from 20.0 grams of na2co3? (molar mass of na = 22.989 g/mol, c = 12.01 g/mol, o = 15.999 g/mol, ca = 40.078 g/mol, h = 1.008 g/mol) 12.2 grams 15.1 grams 24.4 grams 30.2 grams

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

Reactions in cells take place at about a. 40°c b. 0° c. 100°c d. 60°c