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

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

2. Is burning wood a physical or chemical change?

3. Is this mixture homogeneous or heterogeneous?

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

5. Is this mixture homogeneous or heterogeneous?

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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