What is one sign that indicates a physical change? a) matter changes, but no new substance is formed b) a substance changes color when exposed to air. c) something catches fire and turns back d) temperature drops as two liquids are mixed together

The diagram shows a fossil of an ancient whale skull and a skull of a present-day whale. the ancient whale is extinct and is believed to be an ancestor of the present-day whale. what do these skulls most likely show that supports darwin’s theory of evolution? all populations can adapt and survive. only some organisms have a common ancestor. populations change slowly over time. populations rapidly become extinct.

Which chemical equation is unbalanced? which chemical equation is unbalanced

Which particle controls what element an atom is?