Grade 9 science electricity

1. If a light bulb uses 50 J of electrical energy and produces 10 J of light energy, what is the percent efficiency of the light bulb? Show your work! (2 marks = 1 mark for correct formula; 1 mark for answer)

2. Mr. Zajac’s T.V. has a power rating of 200 Watts. During the month of May (31 days), Mr. Zajac watched T.V. for 2 hours per day. The power-supply company charges 8 ¢/kW•h. How much money does Mr. Zajac have to pay the electrical company for his T.V. related energy consumption? Please show your answer in dollars. Show your work! (4 marks)

Electrical energy.

Part B: True or False? 

* Determine if each statement is true (T) or false (F).

12. _______ An element cannot be broken down into simpler chemical substances by any physical or chemical means.

13. _______ If an element is a gas at room temperature, it is likely to be a metal.

14. _______ Elements in the same period of the Periodic Table have varying (different) properties.

15. _______ Hydrogen is a clear, colourless gas that is highly reactive. Based on these properties, Hydrogen is

similar to the Halogens.

16. _______ The element Iodine is a shiny black solid at room temperature. Iodine is thus an example of a metal.

17. _______ Electrical advertising signs made of colourful glowing light tubes are often filled with elements from the  

halogen family.

18. _______ John Dalton proposed the idea of indivisible atoms.

19. _______ Experiments by J.J. Thomson showed that atoms contain neutrons.

20. _______ An atom with 16 protons, 16 electrons and 18 neutrons has a mass number of 50.

21. _______ Elements in group 15 of the periodic table all have 15 valence electrons.

22. _______ Chlorine has electrons in 3 energy levels.

23. _______ When copper is added to tin, the alloy bronze is created. Bronze is an example of a compound.

Part B: True or False? (K – 12 marks)

* Determine if each statement is true (T) or false (F).

12. _______ An element cannot be broken down into simpler chemical substances by any physical or chemical means.

13. _______ If an element is a gas at room temperature, it is likely to be a metal.

14. _______ Elements in the same period of the Periodic Table have varying (different) properties.

15. _______ Hydrogen is a clear, colourless gas that is highly reactive. Based on these properties, Hydrogen is

similar to the Halogens.

16. _______ The element Iodine is a shiny black solid at room temperature. Iodine is thus an example of a metal.

17. _______ Electrical advertising signs made of colourful glowing light tubes are often filled with elements from the  

halogen family.

18. _______ John Dalton proposed the idea of indivisible atoms.

19. _______ Experiments by J.J. Thomson showed that atoms contain neutrons.

20. _______ An atom with 16 protons, 16 electrons and 18 neutrons has a mass number of 50.

21. _______ Elements in group 15 of the periodic table all have 15 valence electrons.

22. _______ Chlorine has electrons in 3 energy levels.

23. _______ When copper is added to tin, the alloy bronze is created. Bronze is an example of a compound.

Atomic #

Mass #

Standard Atomic

Notation

Family Name

p+

n0

e-

Grade 9 Science – Lab Safety & Equipment Woksheet

Part A: Highlight ‘T’ for TRUE OR ‘F’ for FALSE for each of the following questions. (K - 35)

1. T F Broken glassware should be swept up immediately and placed in the garbage bin.
2. T F Eyeglasses or contact lenses are an acceptable substitute for googles during an experiment.
3. T F If you arrive at class to find a spilled liquid on your desk, you should assume it is water and wipe
 it up with paper towels.
4. T F Students with long hair must tie it back when using Bunsen burners.
5. T F If you take too much of the chemicals needed for an experiment, put it back into the container you
 got it from.
6. T F Class B fires are those related to electrical equipment.
7. T F Discard all solid waste by rinsing it down the sink.
8. T F You may consume food and drinks during a lab, as long as it is kept at a safe distance from
 chemicals.
9. T F If asked to detect the odour of a chemical in the lab, the student should inhale a deep breath of the
 chemical.
10. T F If your clothing were to catch on fire, your first step should be to STOP, DROP and ROLL.
11. T F When using a fire extinguisher, aim at the top of the fire. The chemical in the extinguisher will
 fall and put out the flames.
12. T F When heating chemicals in a test tube, heat from the bottom up, aiming the test tube at the
 ceiling, and keep the test tube still.
13. T F It is ok to take off my safety goggles if it’s just for a second while I write something down.
14. T F If any chemical makes contact with your eye, wash it immediately at the eyewash station for
 fifteen minutes. If you should spill chemicals on your skin, place the affected area under water
 immediately.
15. T F Always read through each activity before you begin.
16. T F If you are unsure about any part of the procedure for an experiment, you should figure it out
 yourself. Asking the teacher for clarification will result in a lower mark due to lack of preparation.
17. T F It is acceptable to sit during very long experiments.
18. T F It is ok if I don’t know where the lab safety equipment is since I can just ask someone later.
19. T F Be sure to tell your teacher about any accident, broken equipment, or injury that occurs during
 class; no matter how minor.
20. T F When working with chemicals, keep pens and pencils away from your mouth.
21. T F In warmer months, it is acceptable to wear sandals during an experiment.
22. T F Determine whether your equipment is cool enough to disassemble by placing the back of your
 hand near it.
23. T F Loose-fitting, long-sleeved shirts should be worn during experiments to protect your arms from
 burns and chemical splashes.
24. T F If you must retrieve materials during a lab, it is acceptable to leave your Bunsen burner unattended
 as long as it is set to a yellow flame.
25. T F To avoid an injury when heating materials, always place a stopper or tight-fitting lid on the
 container being heated.
26. T F If a student uses the last of the chemicals in an experiment, it is their responsibility to go into the
 storeroom to retrieve an additional quantity of that chemical.
27. T F Always leave your work area clean and dry before leaving the lab and make sure equipment and
 glassware is returned clean to its proper place.
28. T F Horseplay is O.K. during a lab as long as no one is getting hurt.
29. T F It is never advisable to place a thermometer in an open flame.
30. T F To cool hot glassware, run cold water over it.
31. T F Class A fires can be extinguished with water.
32. T F Class D fires must be extinguished with water.
33. T F Keep equipment away from the edge of the lab bench.
34. T F If your eye itches while you are working with chemicals, you should rub it with your hands.
35. T F WHMIS stands for warning hazardous materials information symbols.