How many grams are in 2.50 moles of copper?

Which of the following statements is true about planck’s law

Ineed ! i have no clue how to do this problem.

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)