You begin with a 50 g chunk of ice. calculate the amount of heat needed to change this ice into50 g of steam.

Compare and contrast physical changes with chemical changes.

What type of matter is made of only one kind of atom

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)