Is phosphorus dissolving in carbon disulfide a chemical or physical change?​

What is impossible to do with a hypothesis

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.

No copying 15 pts how does a free-body diagram tell you about the net force on an object?