What traits do synthesis and decomposition share?

If an area has high air pressure and low humidity, what type of weather will it most likely have? plz !

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.

Light waves can move through , but they travel fastest when they move through a(n) .