When a chemical change occurs, are the properties of the product the same as the reactant?

Which best describes how johannes kepler developed his laws of planetary motion

Can someone me with 6 to 10 plz this is for masteries test.

Observation and experimentation have led many scientists to accept a theory about the origin of the universe. this theory is called the big bang theory. scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. what makes this a scientific theory? (2 points)