6th Grade Science Test Study Guide for Chapter 2. TEST IS FRIDAY!

SCIENCE STUDY GUIDE
TEST 11/21/08

1. What is the difference between endothermic and exothermic reactions?

They are both chemical reactions. Endothermic - Absorbs energy from the surroundings. Exothermic - Releases energy into the surroundings.




2. What molecules make up water AND which one is explosive?

Hydrogen and oxygen make up water and hydrogen is explosive.




3. _______________ is the ability of a substance to go through a chemical change.


Reactivity



4. Substances with ___________________ do not go through chemical changes very easily.

stability

5. What is the ability to burn?
A. stability
B. chemical properties
C. reactivity
D. combustibility

Answer: D

6. A ______________________________ is an exothermic reaction in which a substance combines with oxygen.

combustion reaction


7. In a _______________________________, a substance is broken down in simpler substances.

decomposition reaction


8. Ionic compounds can go through double __________________________, in which they exchange ions with each other.

replacement reactions

9. Modern books are printed on paper in which acid has been neutralized with what?

Modern books are printed on paper in which acid has been neutralized with bases.

10. The original Declaration of Independence is stored in pure helium

because helium is a ___________________________.

nobel gas

11. What chemicals prevent oxidation?

The chemicals that prevent oxidation are antioxidants.

12. What herbs contain natural antioxidants?

A. Sage
B. Clove
C. Rosemary
D. All of the above

Answer: D

13. Freeze drying preserves food by rapidly removing all traces of:
A. Chemicals
B. Water
C. Bacteria
D. Viruses

Answer: B

14. Everything that is matter has different _________________ change.

physical

15. The ____________________________ of a substance determines which physical changes they can undergo.

physical properties

16. What is mass?
A. The feeling
B. The color
C. Weight
D. All of the above

Answer: C

17. _____________________________ is the ability of a substance to be pulled into thin threads without breaking.

Ductility

18. ____________________________ is how the surface of a substance feels.

Texture

19. Does gold have ductility? Why or why not?

Gold does have ductility because it can be pulled into thin strands without breaking.





20. What is the definition of density?

Density is the amount of mass that fits in a given volume.



21. What is the definition of buoyancy?

Buoyancy is the ability to float in liquid or rise in a gas.


22. What are some of the physical properties of a physical change?
A. Number of quarts
B. Shape
C. Size
D. All of the above

Answer: D

23. What might happen in a physical change? Explain or give an example.

In a physical change, the molecules and atoms that make up a substance stay the same.

An example would be a crumpled piece of paper.



24. Name the two reasons gold is used for jewelry. Explain why.

Gold is highly ductile, so it can stretch into strands to form jewelry. Also, gold is highly malleable so it can bend easily to form jewelry.






25. Copper is used for:
A. Jewelry
B. Money
C. Wires
D. All of the above

Answer: D

26. Granite is made up of _____________________,


______________________, and __________________________.

grains of quart, feldspar, and mica

27. Most materials in nature are not

_____________________________.

pure substances

28. If you look closely at a piece of granite, you will see it is also a

_____________________________________.

mixture

29. What are mixtures? Give an example of a mixture.

Mixtures are combinations of two or more pure substances that are not chemically combined with each other. An example of a mixture is cereal or a granola bar.




30. Which seems to be more convenient to separate mixtures, physically or chemically?

Although mixtures can be seperated both physically and chemically, it is easier to separate mixtures chemically.

31. True or False. Substances in a mixture that don’t have different densities separate on their own.

Answer: False

32. An example of a mixture that is not spread evenly is:
A. Cereal
B. Confetti
C. Fireworks
D. All of the above

Answer: D

33. True or False. Gasses can also dissolve in liquids to form solutions.

Answer: True

34. The bubbles in a soft drink are carbon dioxide gas leaving the:
A. Oxygen
B. Hydrogen
C. Solution
D. Calcium

Answer: C

35. True or False. Solids can form some solutions.

Answer: True

36. True or False. Pure silver and pure gold metals are stronger than silver and gold alloys.

Answer: False

37. How do colloids differ from suspensions?

A suspension is a mixture that contains particles that are large enough to be seen. Collids are suspensions that are not easily filtered.



38. If you let orange juice or chocolate milk sit, will the solids in the mixture gradually settle to the bottom of the glass? Explain why.

Yes, the solids in the mixtures of orange juice and chocolate milk will gradually settle to the bottom of the glass because the solids are more dense.