Suggest two reasons why some chemicals remain unchanged in the
environment for a long time

Arock can be broken down into different kinds of substances by physical processes. no chemical reactions are needed to separate different parts of a rock into pure substances. this is because a rock is a(n)

How can you use chemical equations to predict the products of the reaction you can carry out?

Three cards with holes are arranged in a straight line. a light is shined through the first card’s hole and travels through all three cards. what does this tell you about light rays? a) that light is reflected b) that light is refractive c) that light travels in a straight line d) that light does not travel in a straight line