Science in Our World

Chapter 1

7th Science-GIBB

Scientific Method• Definition - the ways in which scientists answer questions

and solve problems

• 6 Steps

1. Ask a question

2. Form a hypothesis

3.Test the hypothesis

4. Analyze the results

5. Draw conclusions

6.Communicate results

7th Science-GIBB

TEKS 7.1 7.2 7.3

6 Steps to Scientific Method

1.

3.4.

5.

6.

2.

• Ask question

– Focus or purpose

– Example: How does sunlight effect plant growth?

• Form hypothesis

– Possible answer or explanation to question

– Use what you know (research)

– Predictions

• If-then statements

– Must be testable

• Testable or Not Testable examples

– Example: If the plant receives little or no sunlight then the plant growth will be limited.

Scientific Method

7th Science-GIBB

TEKS 7.1 7.2 7.3

Scientific Method• Test hypothesis

– Create an experiment that will clearly show if a certain factor causes a given outcome

• Factor- anything in an experiment that can influence the outcome

– Example: The only factor we are testing is the amount of sunlight. We wouldn’t want to water the plants differently or put them in different pots.

– Have a controlled experiment

• Controlled Experiment- uses a control group and one or more experimental group(s), all factors are the same except one

– Example: 3 plants (same type), Plant A receives no sunlight, Plant B receives 2 hours of sunlight a day and Plant C receives the while day’s sunlight

• Variable- the one change that is being tested in the controlled experiment

– Example: amount of sunlight

– Collect data during the experiment 7th Science-GIBB

TEKS 7.1 7.2 7.3

• Analyze results

– Done once experiment is over and all data is collected

– Construct reasonable explanations based on the evidence you collected in your experiment

– Tables, graphs, and charts– Example: see chart

• Draw conclusions

– Do the results support the hypothesis?– It is ok to be wrong

• Communicate results

– Speeches, reports, and repeated experiments

Scientific Method

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Plant A Plant B Plant C

7th Science-GIBB

TEKS 7.1 7.2 7.3

Scientific Models• Definition – representation of an object or system

– Example: Map of Friendswood

• 3 Kinds of Models:– Physical – look like the item they are modeling– Mathematical – made up of mathematical equations and data– Conceptual – system of ideas, groupings, or classification

• Scale models – ratios between model’s dimensions and the object it models remains constant

– Example: maps

• Theory – explanation for hypothesis and observations that have been supported by testing, it explains and predicts

• Law – summary of many experimental results and observations, tells you how things work

7th Science-GIBB

TEKS 7.4

Equipment and Measurement

• Tools for Measuring (examples)– Stopwatch (time)

– Meter stick (length)

– Balances (mass)

– Thermometers (temperature)

– Spring Scales (force)

– Graduated cylinder (volume)

• Tools for Analyzing (examples)– Calculators

– Graphs

– Figures

– Computers

7th Science-GIBB

TEKS 7.4

Equipment and Measurement

• Why do we need these tools?– Measure your desk with hand vs. ruler

• International System of Units (SI)– Almost all countries use this system

– Scientists can share information

– Based on the number 10

– Makes conversions easier

7th Science-GIBB

TEKS 7.4

Equipment and Measurement• Length

– SI unit – meter– KHDMDCM model

• Area– How much surface an object has– 2 measurements: length x width– Expressed as square units, m2, km2, cm2

– What is the area of your textbook?

• Volume– Amount of space something occupies or amount of space something takes up– 3 measurements: Length x width x height

• Volume of boxes– Expressed in cubic units, cm3, L3

– Measured by graduated cylinders • Volume of irregular shaped objects• Amount of water it displaces

– Rock in a graduated cylinder

• Theory – explanation for hypothesis and observations that have been supported by testing, it explains and predicts

• Law – summary of many experimental results and observations, tells you how things work

7th Science-GIBB

TEKS 7.4

Equipment and Measurement• Mass

– Amount of matter– Typically measured in kilograms (large items) or grams

(small items)– Which has more mass, a kilogram of feathers or a kilogram of

bricks?

• Density– Amount of matter in a given volume– 2 measurements: mass / volume– Expressed as g/mL or g/cm3

• Temperature– Measure of how hot or cold something is– Expressed as degrees Fahrenheit, degrees Celsius, or Kelvin

(SI)• Water boils at 212 F and 100 C• Water freezes at 32 F and 0 C• Body temperature is 98.6 F

7th Science-GIBB

TEKS 7.4