Separate the pennies you have into two groups: one group with pennies dated before 1982 and the other with pennies dated after 1982. compare the two groups. record any similarities or differences in size or appearance that you notice between the two groups.

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)