Chapter 1

The World of Science

Section 2 – Scientific Methods in Science

1. When a scientist observes the world they follow a series of steps called the Scientific Method.

2. The Scientific Method follows this order

a. Ask a question

b. Form a hypothesis

c. Test the hypothesis

d. Make observations

e. Analyze the results

f. Draw conclusions

g. Communicate results

3. What is a Hypothesis

a. An explanation that is based on prior scientific research or observations and that can be tested.

b. It is a guess with reason.

4. How can you test a Hypothesis?

a. You need to perform a controlled

experiment.

What makes it controlled?

i. Controlled Experiment-

is an experiment that only tests ONE variable at a time.

ii. Example.

You are making Jell-O and decide to put oranges and pineapple into it. However, you realize that the Jell-O did not harden enough. The next time you take out both the oranges and pineapple, the Jell-O hardened. But which fruit was stopping the Jell-O from hardening?

5. After you test the hypothesis how do you know what the results where?

a. During the experiment you need to observe what is going on.i. That means everything, the Who, What,

Where, When, How, and Why. Using all of your senses.

b. That also means that you need to keep record of your results.

i. This is in case someone wants to replicate your experiment, or just understand why you came to the conclusion that you have come up with.

ii. We analyze our data with charts, and graphs mostly.

6. After we look carefully at our data and draw conclusions.

a. If the hypothesis is not confirmed many scientists will repeat the tests to check for errors.

ii. One error that can happen is that when observing the reactions of the experiment is that if conducted with basis we will subconsciously look for only certain results.

Section 3

Scientific Models

1. What is a model?

a. A pattern, plan, representation or description that shows how something works

i. Concepts

ii. Objects

iii. Systems

2. Types of Models

a. Physical

b. Mathematical

c. Conceptual

3. Physical

a. Models that you can touch.

i. Airplanes, Cars, Dolls

4. Mathematical

a. Made up of equations and data.

i. Graphs, Charts, Tables

5. Conceptual

a. Illustrations and comparisons used to explain ideas.

i. The Big Bang Theory

6. What are Models used for?

a. Models are often used to explain scientific theories

i. A theory is an explanation that ties together many hypotheses and observations.

Section 4

Measurement

1. Most people in the world do not use the same system of measurement that we do.

2. They use the Metric or International System

a. Meter

b. Gram

c. Liter

d. Celsius

e. Kelvin

3. We use this in science so that it is a universal language.

4. Based on 10 so it is easier to convert.

a. Kilo = thousand

b. Deci = ten

c. Centi = hundred

d. Mili = thousand

5. Length

a. Describes how long an object is.

i. Kilometer 1 km = 1000 m

ii. Meter 1 m = 1 m

iii. Decimeter 1 dm = 0.1m

iv. Centimeter 1cm = 0.01 m

v. Millimeter 1 mm = 0.001 m

vi. Micrometer 1µm= 0.0001m

vii. Nanometer 1 nm = 0.00001 m

6. Volume

a. Measures the size of a body or the region in 3-D space.

i. Liter (L)

ii. Milliliter mL

7. Mass

a. The amount of matter contained in an object.

i. Kilogram 1 kg = 1000 g

ii. Gram 1 g = 1 g

iii. Milligram 1 mg = 0.001 g

8. Temperature

a. Measures how hot or cold an item is.i. Celsius

1. 0o = freezing point of water

2. 100o = boiling point of water

ii. Kelvin

1. 272o = freezing point of water

2. 373o = boiling point of water

9. Density

1. Is the ratio of mass a substance is to the volume is

2.