How can you tell that a chemical change has occurred?
O
A. The products of the change are different from the starting
substances.
O
B. The products of the change are warmer than the starting
materials.
O
C. Two or more substances are mixed together and form a solution.
D. The materials that you are working with evaporate.

Where are chemicals found at work? a. only in cleaning products b. only in carpets and paint c. in every area of work d. only in food preparation submit

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

Which of the following observations indicates that there is a small, dense, positively charged part in the center of an atom? some uncharged particles are scattered by a gold foil. all uncharged particles are attracted towards a gold foil. all positively charged particles pass straight through a gold foil. some positively charged particles bounce back from a gold foil.