1. Ch 2 Clicker Review
Elements, Mixtures, Compounds, Changes, and the Law of Conservation of Mass

2. 1. How can you tell pure substances from mixtures
Pure substances have a symbol or formula
Pure substances have to be broken down by chemical changes
Both A & B are correct
None of the above

3. 2. Is burning wood a physical or chemical change?

4. 3. Is this mixture homogeneous or heterogeneous?

5. 4. Is dissolving salt into water a physical or chemical change?

6. 5. Is this mixture homogeneous or heterogeneous?

7. 6. What is the difference between physical & chemical changes?
Chemical changes change into a different substances
Physical changes require reactions to change
Chemical changes change the shape
Chemical changes change the phase of the matter
All of the above

8. Doubled Subtracted Rearranged
7. The law of conservation of mass states that matter cannot be created or destroyed it can only be ______
Doubled
Subtracted
Rearranged

9. 8. Is Gold (Au) an element, a mixture, or a compound?

10. 9. Is brass an element, mixture, or compound?

11. 10. Is your desk an element, mixture, or compound?

12. 11. Is carbon dioxide an element, mixture, or compound?

13. 12. What phase state is oxygen normally in?
solid
liquid
gas
plasma

14. 13. What phase state is lightning?
solid
liquid
gas
plasma

15. 14. What phase states are shown?
Solid & liquid
Solid & gas
Liquid & gas
Solid & Plasma
Gas & plasma

16. 15. Which of the following is an example of a heterogeneous mixture?
salt water
orange juice with pulp
syrup
vinegar

17. 16. What is true about elements?
contain a single kind of atom
predictable properties
combine to form compounds
all of the above
none of the above

18. 17. A substance that undergoes a phase change from liquid (water ) to gas (steam)
Keeps its formula
Loses some mass
Gains some mass
Changes its formula

19. 18. If you melt a copper penny what will happen to its mass?
increase
decrease
stay the same

20. 19. What technique would separate a suspension?
filtration
magnetism
crystallization
distillation

21. 20. What technique would separate salty water?
filtration
evaporation
crystallization
floatation

22. 21. Floatation works when parts of a mixture have different
masses
volumes
densities
all of the above

23. 22. Knowing the chemical properties of a substances tell us
how it reacts with other substances
how it smells
how it looks
nothing

24. 23. When the copper penny turned silver color in zinc & NaOH
it was a chemical change
It was a physical change
it was an element
it was a compound

25. 24. Which of these methods will result in a chemical change?
warming
melting
burning
All of the above

26. physically chemically
25. When you digest your lunch, are you physically or chemically changing the food?
physically
chemically