What is classified as a pure substance.
a: compound
b: colloid
c: solution
d: homogeneous mixture

Which of the following electromagnetic waves can create ions?

Hey can you me with this i really need y’all

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)