1. Study Guide
3rd Quarter Exam

2. What is a hypothesis? a testable prediction

3. What are the steps of the Scientific Method?
State the problem, research, hypothesis, test hypothesis, conclusion

4. Define independent and dependent variables and indicate which axis each is located on.
independent-the variable you change to see how it will affect the dependent variable; X axis
dependent- a factor that changes in an experiment from manipulation of the independent variable; Y axis

5. What type of graph should be used to show how the temperature changes over the course of one year?
Line graph

6. Independent variable- amount of water
John has three tomato plants. He waters them twice a day for two weeks and measures their growth daily. Each plant is the same size at the start of the experiment and the same type of soil is used for each plant. He gives Plant A 50 ml of water, Plant B 100 ml of water (recommended amount – used for comparison), and Plant C 200 ml of water twice daily. Identify the following:
Independent variable- amount of water
Dependent variable- growth of plant
Control- plant B
Constants frequency of watering, type and size of plants, soil type and amount
Possible hypothesis: If plants receive the optimum amount of water, then they will grow the tallest.

7. Green plants convert light energy from the sun into what type of energy in the process of photosynthesis?
chemical potential

8. Where does the energy that travels through Earth’s ecosystems come from?
the sun

9. How do most cells release the energy stored in glucose?
Cellular respiration

10. What is a food chain?
the feeding relationships between a producer and a single chain of consumers

11. What is a food web?
the feeding interactions of all the food chains in an ecosystem

12. What role do consumers play in a food web?
consumers eat producers or lower level consumers to get energy from the sun

13. What role do producers play in a food web?
Producers use carbon dioxide, water and sunlight to make sugars they store 

14. What happens to most matter when it is heated?
The particles gain KE and break attractions to neighboring particles; they take up more space

15. What behavior of water is unusual?
Water expands as it goes from liquid to a solid (most other substances contract) due to its polarity

16. Compare the speed of the particles in a solid compared to a gas.
Particles move much slower (vibrate in place)

17. List the characteristics of a… solid
Definite volume
Definite shape
Crystalline, orderly particle structure
Particles held tightly in place
Least amount of KE

18. List the characteristics of a… liquid
Definite volume
No definite shape
More KE than a solid, but less than a gas
Enough KE to escape orderly arrangement
Can flow

19. List the characteristics of a… gas
No definite volume
No definite shape
Most KE

20. Define a mixture. Give an example.
a material made up of two or more substances that can be easily separated by physical means; salt water, pizza, trail mix

21. Define chemical change. Give an example.
a change in which new substances are produced
Ex>Rusty nail   

22. Define physical change. Give an example.
a change in size, shape, or state of matter Ex>Melting an ice cube, ripping a sheet of paper in half

23. What do electron dot diagrams represent
What do electron dot diagrams represent? Draw the electron dot diagram for H and Cl
electrons in the outermost energy level

24. Why are the noble gases considered stable?
They have a full outer energy level

25. Define: a. atomic number-the number of protons in an atom b
Define: a. atomic number-the number of protons in an atom b. atomic mass-weighted average mass of all isotopes for an element c. mass number- protons +neutrons in the nucleus d. average atomic mass-weighted average mass of all isotopes for an element

26. What is an isotope? Give an example.
Atoms of the same element with different numbers of neutrons. Ex> carbon-12, carbon-13, and carbon-14

27. Draw and label the parts of an atom and subatomic particles.

28. Water is a polar molecule. What does this mean?
there is unequal sharing of electrons in bonds between atoms leading to regions of slight charge

29. How is a nonpolar molecule different than a polar molecule?
There is equal sharing of electrons in nonpolar molecules

30. Slight positive cancels out the slight negative charge Ex> water
Although some molecules have a slightly positive and a slightly negative end, the overall molecule is neutral. Explain why or illustrate why this is true.
Slight positive cancels out the slight negative charge Ex> water

31. Why do atoms combine to make compounds?
To achieve stability by filling valence shells with electrons

32. Give an example of the properties of a compound being different than the properties of the elements that make them up.
Salt being formed from sodium and chlorine Copper sulfate being formed from copper, sulfur, and oxygen

33. When is an atom considered stable?
When the outermost energy level is filled with electrons

34. What is a chemical formula? Give one example.
Shows elements a compound contains and the exact number of the atoms of each in a unit of that compound Ex. H2O, NaCl

35. What is the difference between a covalent and ionic bond?
Between metals and nonmetals
Between nonmetals
Transfer of electrons
Form ionic compounds
Sharing of electrons
Form molecules

36. How many hydrogen atoms are present in one molecule of ammonium acetate, NH4C2H3O2?7

37. What is the pH scale used for?
To measure the concentration of H+ ions in a solution

38. If a substance has a pH of 1, is it a strong acid or a strong base?

39. Sugar is the solute and water is the solvent
When sugar is dissolved in water to make a solution, which substance is the solute and which is the solvent?
Sugar is the solute and water is the solvent

40. What is the difference between saturated and unsaturated fats?
Saturated fats have all single bonds between carbon atoms in the fatty acid chains

41. How are polymers created from monomers (name the process)?
Polymerization reactions (dehydration synthesis)

42. List the four macromolecules, the main function(s) of each, the monomer each is made of (or structure if no monomer is present), and an example of each.
Macromolecule
  Carbs
Lipids
  Nucleic
Acids
Proteins
Function(s)
 energy and structure
 long term energy, insulation, structural(cell membrane)
 encoding and transmitting genetic info
 enzymes, transport in body, structural
Monomer/ structure
 monosaccharides (glucose)
No monomer
Nucleotides
Anino acids
Example
 starch, glycogen
Fats, oils, phospholipids
DNA, RNA
Hemoglobin, insulin

43. What makes carbon special?
4 valence electrons make it capable of forming many diverse compounds

44. How many bonds can carbon form?4

45. When disaccharides are changed to monosaccharides, what chemical process is used?
hydrolysis