Today's Quiz Evidence of Chemical Changes

1.What does "Cool, Girls, Love, Their, Phones" stand for?

2. Which if the following is not evidence of a chemical change?

• production of gas
• color change
• change in thermal energy
• change in state of matter

3. Which of the following results in a substance transforming into a completely new substance?

• chemical change
• chemical property
• physical change
• physical property

4. A student noticed a solid substance was formed when mixing two clear liquids during a lab. What evidence of a chemical change is represented?

• production of gas
• change in thermal energy
• production of a precipitate
• color change

5. Which of the following is evidence of a chemical change due to color change?

• coloring a sheet of paper with crayons
• mixing food coloring and water
• burning a sugar cube and it turns black
• melting a solid colored wax into liquid

6. Which of the following is an accurate statement about chemical changes?

• chemical chnages result in the formation of substances with the same properties
• the new substances formed have different properties than the orginal substances
• the new substances formed have the same composition as the original substances
• chemical changes can be easily reversed.

7. A student observed fizzing and bubbling when an antacid tablet and water were combined. Which of the following correctly identifies the evidence that a chemical change occurred?

• production of gas
• change in thermal energy
• production of precipitate
• color change

8. A student conducts an investigation on the growth of mold on a piece of bread. Which of the following is evidence that a chemical change has taken place?

• the piece of bread begins to change color as mold appears
• the piece of bread gives off heat as mold appears
• the piece of bread produces a precipitate
• the piece of bread bubbles and fizzes as mold appears.

9. Answer the question below.

• A
• B
• C
• D

10. Lead nitrate and Potassium iodide are both clear liquids when in solution. When we mix these two solutions a yellow solid is formed. What observation suggest a chemical change has occurred? Explain.