Name: ______Date: ______Period: ______
ENERGY UNIT MAJOR TEST 2/8 & 2/9
MOLECULES
1. What is the difference between mixtures, atoms, elements, compounds, & molecules?
a. mixtures - ______
______
b. atoms - ______
______
c. elements - ______
______
d. compounds - ______
______
e. molecules - ______
______
2. What is the chemical formula for each of the molecules below?
a. water ______b. ammonia______c. carbon dioxide______d. methane______
3. What can you infer about the water molecules?
______
4. Check ALL that apply.
Chemical Formula / Element / Compound / MoleculeCl
O3
HCl
MgCl2
CCl2
KMnO4
5. What are Valence electrons?
______
______
______
6. What are ions? ______
______
7. What is does the coefficient mean in this chemical formula? 5H2O ______
8. What does the subscript (small number) mean in this chemical formula? 5H2O
______
ELECTROMAGNETS
9. How can you increase the strength of an electromagnet?
a. ______
b. ______
10. What are the energy transformations in the electromagnet?
______
11. What conclusion can you make about the data below?
Electromagnet ExperimentLength of
wire / Number of
coils / Number of
batteries / Number of
paper clips
20 / 50 / 1 / 15
20 / 100 / 1 / 29
40 / 50 / 1 / 16
40 / 100 / 1 / 31
______
12. Would increasing the number of batteries in a circuit that is connected to a small electric motor affect the speed of the motor, if all other variables are kept constant?
______
13. Draw all the possible ways for bar magnets to attract or repel.
14. Describe the static electricity between a balloon and your hair.
______
15. What makes magnetic objects different from nonmagnetic objects? ______
______
16. How do electric motors work? ______
______
POTENTIAL & KINETIC ENERGY
17. Use the roller coaster and describe the potential and kinetic energy using the graphs at points A, B, C, & D.
A. ______
B. ______
C. ______
D. ______
18. Make a conclusion from the graph below. ______
19. Label the PE & KE at each point at the pendulum swings.
A. ______
B. ______
C. ______
D. ______
20. How can you increase potential energy? ____________
21. How can you decrease kinetic energy? ______
22. What is the difference between potential & kinetic energy?
______
23. Put the books in order of least to greatest potential energy. EXPLAIN.
______
24. What is energy?
______
Name: ______Date: ______Period: ______
ENERGY UNIT MAJOR TEST 2/8 & 2/9
MOLECULES
1. What is the difference between mixtures, atoms, elements, compounds, & molecules?
a. mixture – a substance made by combining two or more different materials in such a way that no chemical reaction occurs.
b. atoms are the basic building blocks of all matter.
c. elements are a substance consisting of a single type of atom.
d. compounds form when two or more different atoms chemically combine together.
d. molecules form when two or more atoms chemically combine together.
2. What is the chemical formula for each of the molecules above?
a. waterH2Ob. ammoniaNH3c. carbon dioxide CO2 d. methane CH4
3. What can you infer about the water molecules below?
For every Oxygen atom there are two Hydrogen atoms.
4. Check ALL that apply.
Chemical Formula / Element / Compound / MoleculeCl / X
O3 / X / X
HCl / X / X
MgCl2 / X / X
CCl2 / X / X
KMnO4 / X / X
5. What are Valence electrons?
Valence electrons are electrons on the outermost energy level of an atom. Chemical bonding occurs on the outermost energy level where electrons are shared or exchanged (gained or lost)
6. What are ions?
Ions are formed when an atom gains or loses an electron. The ion can be positive if electrons are lost and negative if electrons are gained.
7. What is does the coefficient mean in this chemical formula? 5H2O
8. What does the subscript (small number) mean in this chemical formula? 5H2O
ELECTROMAGNETS
9. How can you increase the strength of an electromagnet?
a. increase the number of coils
b. increase the voltage (number of batteries)
10. What are the energy transformations in the electromagnet?
Chemical to electrical to electromagnet
11. What conclusion can you make about the data below?
Electromagnet ExperimentLength of
wire / Number of
coils / Number of
batteries / Number of
paper clips
20 / 50 / 1 / 15
20 / 100 / 1 / 29
40 / 50 / 1 / 16
40 / 100 / 1 / 31
If you increase the number of coils you increase the strength of the magnet. The supporting evidence is the number of paper clips is directly proportional to the number of coils.
12. Would increasing the number of batteries in a circuit that is connected to a small electric motor affect the speed of the motor, if all other variables are kept constant?
Yes, the motor would run faster because the increased electrical force increases the magnetic force in the motor.
13. Draw all the possible ways for bar magnets to attract or repel.
14. Describe the static electricity between a balloon and your hair.
15. What makes magnetic objects different from nonmagnetic objects?
Electrons spin in the same direction
16. How do electric motors work?
They convert electrical energy into kinetic energy.
POTENTIAL & KINETIC ENERGY
17. Use the roller coaster and describe the potential and kinetic energy using the graphs at points A, B, C, & D.
A. highest point PE = 100% KE = 0%
B. KE has increased as the PE has decreased
C. PE has increased as the KE has decreased
D. KE is at its greatest and PE is at its lowest, the coaster is going the fastest at this point
18. Make a conclusion from the graph below.
When the PE is low the KE is high.
19. Label the PE & KE at each point at the pendulum swings.
A. PE is highest KE is lowest
B. KE Is highest PE is lowest, moving the fastest
C. PE starts to increase as the KE decreases
D. PE is highest KE is lowest
20. How can you increase potential energy?
Increase the height of the object or the mass of the object
21. How can you decrease kinetic energy?
Decrease the speed and decrease the mass
22. What is the difference between potential & kinetic energy?
Potential energy is stored energy or energy due to position
Kinetic energy is energy of motion
23. Put the books in order of least to greatest potential energy. Explain.
Books C, A, B.
Book C has the least PE because it has the least height.
Book A has less more PE than Book C because it is on a higher shelf.
Book A has less PE than Book B because it has less mass.
So Book B has the most PE because it the highest and has the
most mass.
24. What is energy?
The ability to do work, the ability to cause change