Science overview slides

Density

Review:

• Matter: Anything that has volume and takes up space

• Mass: The amount of matter in an object

• Volume: The amount of space an objects takes up

Density

• Property of matter that describes the relationship between its mass and volume

• Describes how closely packed its atoms are

A measure of mass per volume

Density:

D =

How to calculate density (D):

Calculating Density

Remember:

1 mL = 1 cm3

Density:

massDVolume

=

Units:g

mL or cm3

Density Units (Labels)

g/cm3

Density:

OR g/mL

massDVolume

=

The density of water is 1 g/mL

Matter with a higher density will _____.

Matter with a lower density will _____.

Density of Materials

Each material has a UNIQUE density:

An object has a mass of 12 g and a volume of 4 mL, what is it’s density?

Will it sink or float in water?

Example:

An object has a mass of 3 g and a volume of 4 mL, what is it’s density?

Will it sink or float in water?

Example:

An object has a mass of 99.84 g and a volume of 12.8 mL, what is it’s density?

Example:

What is the object in the previous problem made of?

Floats!!

Saturn

Golf Ball

Sinks!

Pumice

Floats!!

Gasoline

Floats!!

Corn Syrup

Sinks!!

Vegetable Oil

Floats!!!

The Metric System

Problems?

• How many ounces in a gallon? 128

How many inches in a mile? 63360

How many ounces in a pound? 16

Metric Base Units

Meter (m)

*Measures distance

*Ex: length of room

Metric Base Units

Gram (g)

*Measures mass

*Ex: mass of a penny

Liter (L)

*Measures volume

*Ex: volume of pop

Metric Base Units

Celsius (˚C)

*Measures temperature

* freezing water 0˚C

* boiling water 100˚C

* body temp 37˚C

Metric Base Units

Metric PrefixesBase Units

meter (m)

liter (L)

gram (g)

deci

(d)

centi

(c)

milli

(m)

deka

(da)

hecto

(h)

kilo

(k)

increasing decreasing

1000 100 10 .1 .01 .0011

Problems? Not at all…

How many cm in a meter? 100

How many mL in a L? 1000

5 kg is how many grams? 5000

Safety Trivia

Play it safe (unlike this guy!)

1. In the lab, you are going to be working with an open flame. Describe two safety precautions you should follow to complete the lab safely.

2. Describe one thing that the students are doing incorrectly in this picture.

3. Your lab partner drops a beaker which shatters on the lab surface. Describe two safety rules that should be followed in this situation.

4. During a lab, you use hydrochloric acid. What should you do with the acid after the lab is complete?

5. During the lab with hydrochloric acid, your lab partner gets some of the acid on her fingers. What precautions should be taken so that her skin doesn’t burn?

6. A classmate offers you some water from a beaker being used in an experiment. How will you handle this situation?

7. What should a student do if they get something in their eye?

8. A student has long hair. You will be doing a lab using a Bunsen burner. What should that person do before starting the lab?

9. A lab has many powdered chemicals that are used to complete it. What should you do before leaving the room for your next class?

10. When using electrical equipment in a lab, describe two safety precautions that should be followed.

11. A student’s clothing starts on fire. What should you do?

12.Before starting any lab procedure, you should always_________________________________.

13. Describe two safety practices that the students in the picture are following correctly.

14. Describe two things that you would do if this happened at your lab station.

15. What safety procedure is not being followed in this picture?

16. Why is this situation life threatening?

17. What should you do in this situation?

18. Why is acid stored in a glass or heavy plastic container?

19. You are about to start a lab when you notice the test tube has a crack in it. What should you do?

20. When you and your lab partner finish a lab, what is your responsibility before you leave the classroom?

21.What is the procedure in the picture called?

22.Why is it important to use this procedure in a lab setting?

BONUS!

Scientific Method

Gotta follow the steps!

Steps of Scientific Method

• 1. Ask a Question/Problem– Ex: What is the ideal amount of water for optimum

grass growth?


• 2. Research and Collect Information– Find out as much information

• Ex: Ask a nursery owner, landscaper, internet, books, etc.


• 3. Form a hypothesis (IF, THEN, BECAUSE)– Ex: If grass gets 20 minutes of watering each day, then

it will grow the most because water is necessary for cell growth.


• 4. Test the Hypothesis by Experimenting and Collecting Data– Ex: What would the experiment look like?

What type of data would you collect?


• 5. Analyze the Data – Ex: Make graphs, charts, tables, etc.


• 6. Draw a Conclusion – Answer the original question

– Give a reason for your conclusion

– Include data (numbers!) to back up your answer

Variable

• The factor in an experiment that can change– Ex: Amount of watering of lawn

Hypothesis

• An educated guess or testable statement– Ex: Irish people are smarter than other

people.

Observation

• Gathering information using the senses and/or equipment– Senses:

• Sight

• Touch

• Taste

• Sound

• Smell

Prediction

• Use of knowledge to identify and explain observations or changes in advance– I predict the Vikings will beat the Lions

Inference

• The development of ideas based on observations– Example…You’ll see.

Fact

• An observation that has been repeatedly confirmed– Ex: Lead is more dense than Styrofoam

Law

• A descriptive generalization about how some aspect of the natural world behaves under stated circumstances– Ex: Newton’s Laws of Motion

Theory

• A well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences and tested hypotheses.– Ex: Cell Theory and Theory of Relativity