HELP PLEAS compare the structure and bonding of the three compounds carbon dioxide magnesium oxide and silicon dioxide

What overall charge must all compounds have

Voltaic cells produce a positive overall charge. what does this indicate? a. the reaction is likely to be endothermic. b. the reaction is spontaneous. c. the reaction is not likely to occur. d. the reaction is not spontaneous.

What does a complete balanced chemical equation include? a. exothermic coefficients b. endothermic coefficients c. valence electrons d. molar coefficients