Which of these is an example of a physical change? sugar dissolving in warm water
iron rusting in the presence of moist air
wood burning in the presence of oxygen
baking soda reacting with acid to form a gas

How does a hydroelectric power plant converts energy into energy.

George is a dalmatian puppy. describe what happens to light that allows you to see george’s black and white coat.

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.