What is the difference between a solid and a gas

Which compound contains both ionic and covalent bonds? a) hbr b)cbr4 c)nabr d) naoh

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.

The valence of aluminum is +3, and the valence of the chlorine is -1. the formula fir the aluminum chloride is correctly written as