Safety and Scientific MethodSafety and Scientific Method

Lab Rules

Use only the equipment and materials required for your lab

Read directions Wear your goggles Think and act safely Stay at your station unless materials

are needed or there is an emergency Clean up and return all materials

Lab Safety

Safety rules are found in your text and on a handout.

You have been quizzed over the rules and you must pass the quiz in order to participate in lab activities.

Lighting your Bunsen burner

Turn the knob on the burner so that it is not completely closed

Be sure gas connection is good Light the match Turn on the gas

Turning off your burner

Turn off the burner at the gas source, not at the burner

When the handle is perpendicular to the gas jet, the gas is off.

NEVER, NEVER Never throw matches in

the sink! Put them on the table.

Later, when cool, or after wetting, throw them in the trash.

Lab Equipment

Identify each of the following:

flask

Screenand burner

microscope

beakerTest tubes and rack

1

2 3

4

5

6

7

8

9

1011

clamp

ring

Ring stand

Wire screen

Erlenmeyerflask

Magnifying glass

12

1313

14

Florenceflask

Erlenmeyerflask

Graduated cylinder

15

16

Electronic scale

chicken

What belongs in my lab drawer?

• Goggles- 2 or 3 pair• Wire screen• Bunsen burner• Test tube holder• Test tube brush• Tongs• Test tube rack (this

belongs in the cubby above your drawer)

Scientific MethodScientific Method

• State the problem

• Gather information

• Form a hypothesis

• Test the hypothesis

• Record and analyze data

• State a conclusion

• Repeat the work

Controls and VariablesControls and Variables

Only one variable in an experimentOnly one variable in an experiment

It is important to control all other It is important to control all other factorsfactors

Inferences & ObservationsInferences & Observations

Observation = anything taken in through Observation = anything taken in through the senses (see, hear, taste, smell, the senses (see, hear, taste, smell, touch, or taste)touch, or taste)

Inference = statement that explains the Inference = statement that explains the observations or conclusion based on observations or conclusion based on observationsobservations

Ex: Suppose your friends went to the Ex: Suppose your friends went to the beach at noon on a warm day and saw beach at noon on a warm day and saw some black and white birds. Which of some black and white birds. Which of the following are observations and the following are observations and which are inferences? which are inferences?

1. It is summertime.

2. It is day time.

3. They saw birds.

4. They saw seagulls.

5. They went swimming.

6. One friend’s name was Bob.

7. It was a warm day.

8. The birds were black and white.

9. They ate lunch and drank Coke.

10. The people are friends.