Topic 1: Introduction

Earth Science

I. OBSERVATIONS & INFERENCES

I. Observations & Inferences

A. Observations• The measuring or

observing something using your Five Senses.– Sight– Smell– Touch– Hear– Taste

B. Inferences• An interpretation

(guess) based on your observations.

Practice Questions: Observation or Inference

1. The dog’s tongue is hanging out. ___________2. The dog is thirsty. _____________________3. The rock is smooth, gray and contains quartz.

__________4. The rock formed below the earth’s surface.

_________5. The sky contains a lot of clouds.

_______________6. A storm is coming soon. __________________

C. Classification:The grouping of items by using similar characteristics.

• How would you classify the following things:

D. Measurements• An observation that is compared to a known

standard. Usually made with an instrument.– Examples:

• Mass (grams, kilograms, pounds, ounce)• Length (meter, foot, mile, kilometer)• Time (minute, second, hour)

1. Rounding Numbers: Unless otherwise stated, ALL measurements and calculations MUST be rounded to the nearest tenth.

(Ask yourself, “How many zeros are in the #10?)

7.369cm =

2. Averaging Numbers: When you calculate an average, you simply _____ the numbers and then ________ by the number of digits you added.

Now it’s your turn… Find the averages of the following values and round your answer to the nearest 10th.

1st Value 28.0 2.117 127.9 50.0 35.678

2nd Value 34.0 6.89 404.0 70.0 35.985

3rd Value - - 543.5 60.0 35.789

Average          

II. GRAPHING RELATIONSHIPS & CHANGE

A. Graphs:Method of organizing and comparing data

(variables) making it easy to read.

1. Independent Variable:Variable that stands alone and is compared to.

Ex) Time

2. Dependent Variable:Variable whose changing value is measured.

Ex) Mass, Volume, Temperature

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5

10

15

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Temperature (oC)

Time (min)

Tem

pera

ture

(C)

Time (min) Temperature (oC)

0 301 332 383 404 415 426 437 448 459 45

10 45

B. Graphing Relationships:1. Direct Relationship:

Where both variables are changing in the same way.2. Indirect Relationship:

Where the two variables are changing in opposite ways.3. Cyclic Relationship:

Where the two variables change in a reoccurring pattern.

C. Rate of Change:How much that is measured (field) changes

over time.

Rate of Change = ---------------------------------------------

The greater the Rate of Change the Steeper the Slope of a graph.

Which letter has the greatest rate of change? How do you know?

Problems: using your graph from the previous page1. Calculate the Rate of Change for time 0 – 5min.

2. Calculate the Rate of Change for time 5 – 10min.

3. Calculate the Rate of Change for time 0 – 10min.

1. Rate of Change and Graphs• Which of the following three graphs has the greatest

rate of change? Explain how you know.

• Graph C because it has the steepest slope.

The greater the Rate of Change the Steeper the Slope of a graph.

2. Prediction of Change:an inference about the conditions and

behavior of the variables in the future.

• Using the graph you created on the previous page, can you predict what the temperature might be at time 15 minutes?

0 1 2 3 4 5 6 7 8 90

5

10

15

20

25

30

35

40

45

50

Temperature (oC)

Time (min)

Tem

pera

ture

(C)

Time (min) Temperature (oC)

0 301 332 383 404 415 426 437 448 459 45

10 45

2. Prediction of Change:an inference about the conditions and

behavior of the variables in the future.

• Using the graph you created on the previous page, can you predict what the temperature might be at time 15 minutes?

D. Dynamic Equilibrium:When opposing environmental variables

cancel each other out reaching a point where both variables are the SAME (equal).

Do Now:1. Describe the objects on the desk.2. Infer what you think will happen when

the Coke/Pepsi can is placed in the water?

3. Infer what you think will happen when the Diet Coke/Diet Pepsi can is placed in the water?

4. What actually happened?

5. What do you think is responsible for the outcome you observed?

Coke Diet Coke

III. DENSITY

III. DENSITY

III. Density:The amount of MASS (stuff or matter) in a certain VOLUME (space).

DENSITY = -----------------MassVolume

Density Triangle

Only works if you know 2 of the variables!

A. Mass:The amount of matter (stuff) an object contains. Usually measured with a balance.

B. Volume:The amount of space an object takes up. Can be (1) calculated or (2) measured with a graduated cylinder.

1. To calculate the volume using a ruler:

Volume = Length x Width x Height

ml

• Pour water in a graduated cylinder & record the measurement.

• Drop in the object & record the new water measurement, then SUBTRACT!

2. To measure the volume using a graduated cylinder:

Example in Notes

Practice Problems:1. Find the DENSITY of a rock with a mass of 200.8g and a

volume of 15.4mL.

2. Find the MASS of an object with a density of 17.3 g/cm3 and a volume of 26.9 cm3.

Practice Problems:3. Find the VOLUME of an object that has a density of 12.7

g/cm3 and a mass of 253.7 grams.

C. Determining Relative Density:The density of water is ________ or _________

What is the difference between the two units?

1. An object with a density LESS then 1.0g/mL will FLOAT in water.

2. An object with a density MORE then 1.0g/mL will SINK in water.

D. Physical Changes that Affect Denisty:- Two things can change the density of an object:

1. Temperature:Increase in temp will cause an object to expand (volume increases so DENSITY will ______________.

2. Pressure:Increase in pressure will cause object to contract

(volume decrease) so DENSITY will ______________.

THE DENSITY OF AN OBJECT WILL NOT CHANGE UNLESS YOU CHANGE THE

TEMPERATURE OR PRESSURE!!

Questions:1. The amount of space a substance occupies is

called __________________.2. An empty 250mL beaker has a mass of 60g.

When 100mL of oil is added to the beaker, the total mass is 140g. Determine the density of just the oil.

3. A student mixed several different types of beads that all have a size of 12mm. They were lucky that the beads had different densities. One group of beads had a density of 0.6g/cm3; the other beads had a density of 1.2g/cm3. Describe a method that the student can use to sort the beads?

a) Which material has the greatest density; Explain how you know?

b) Draw the line which would represent the density of water.

c) Since you know the density of water, which of these materials will float; Explain how you know?

4. Using the container to the right which is filled with water, list the four materials is order of INCREASING Density.

5.Which of the four materials has a density closest to water? Explain how you know.