Science

Grade 9, second quiz

How to wright a hypothesis

If____, then_______ [this] will happen, because…….

How to ask a question

What is the effect of _____ on ______?

What is an independent variable?

A factor that is changed by you.

What is a dependant variable?

The response that is measured.

What is a controlled Variable?

A variable that is held constant to keep the experiment “fair”.

What is a test group?

The group in an experiment that receives the treatment or variable being tested.

What is a control group?

A control group is the group in an experiment that does not receive the treatment or variable being tested. It is kept under normal or baseline conditions so that it can be compared with the test group to see if the independent variable had an effect.

What are the steps of the Scientific Method?

1. Observation-(research)

2. Question (What is the effect of_____ on ______?)

3. Hypothesis (If,then,beacasue)

4. Experiment

5. Analyze (My hypothesis was supported my hypothesis is not supported).

What makes a good question?

1. Realist (possible to answer)

2. Simple, specific, and research able

3. Compares 2 variables

4. NO “why” questions

What is science?

A way of understanding the universe through observation and experiment. The goal is to make accurate predictions.

What are the 5 steps of the scientific method?

1. Make an observation 2. Ask a question 3. Make a hypothesis 4. Make an experiment to test the hypothesis 5. Analyze whether the hypothesis was supported.

What is the first step of the scientific method?

Make an observation.

What is the second step of the scientific method?

Ask a question.

What is the third step of the scientific method?

Make a hypothesis that is testable.

What is the fourth step of the scientific method?

Make an experiment to test the hypothesis. The experiment needs to be measurable.

What happens if a hypothesis is supported?

You gain more knowledge and can ask more questions, returning to step 1.

What happens if a hypothesis is not supported?

Think of a new hypothesis or a new experiment and return to step 3 or 4.

What is a scientific theory?

A successful explanation that makes accurate predictions and is supported by consistent, repeated experimental results.

What are examples of scientific theories given in the lectures?

Gravity, natural selection, and germ theory.

Why do scientific theories change?

Science is continually evolving as new observations can change old theories.

What makes a good scientific question?

It is realistic, simple, specific, measurable, and compares the effect of something on something else.

What should a good scientific question NOT contain?

A "why" question.

What is a useful format for a scientific question?

"What is the effect of ______ on ______?"

Is "What effect does the type of birdseed have on the number of birds that visit?" a good scientific question?

Yes. It is specific, measurable, and compares the effect of one variable on another.

Is "Why is the sky blue?" a good scientific question for this experiment format?

No. The lecture states that good experimental questions should not be "why" questions.

What is a hypothesis?

An educated guess that must be testable.

What format should a hypothesis use?

"If _____, then _____, because _____."

What does the "if" part of a hypothesis describe?

What you will change or do.

What does the "then" part of a hypothesis describe?

What you predict will happen.

What does the "because" part of a hypothesis describe?

The background information or reasoning supporting your prediction.

Does a hypothesis have to be correct?

No. It is okay if a hypothesis is wrong.

What is an independent variable?

A factor that is changed by you.

What is a dependent variable?

The response that is measured.

What is a controlled variable?

A variable that is held constant to keep the experiment fair.

How many independent variables should you change at one time?

One. Changing more than one means the experiment will not be controlled.

In "Sunlight makes a plant grow tall," what is the independent variable?

The amount of sunlight.

In "Sunlight makes a plant grow tall," what is the dependent variable?

The height of the plant.

What is an experiment?

A procedure used to test a hypothesis by changing the independent variable and observing what happens to the dependent variable.

What is an experimental/test group?

The group in which you change something.

What is a control group?

The group in which you do not change anything.

In an experiment about water temperature and how much sugar dissolves, what is the independent variable?

The temperature of the water.

In an experiment about water temperature and sugar, what is the dependent variable?

The amount of sugar that can be dissolved, measured in grams.

What are controlled variables in the water-temperature/sugar experiment?

The container, type of water, brand of sugar, and shape of sugar.

What is the test group in the water-temperature/sugar experiment?

Warm water.

What is the control group in the water-temperature/sugar experiment?

Room-temperature water.

In the mouse salt-diet experiment, what is the independent variable?

The salt content of the diet.

In the mouse salt-diet experiment, what is the dependent variable?

The body mass of the mouse.

What were controlled variables in the mouse salt-diet experiment?

Amount of water, cage size, mouse breed/species, room temperature, and duration of the experiment.

In the basketball experiment, what is the independent variable?

The volume of air in the basketball.

In the basketball experiment, what is the dependent variable?

The height of the bounce.

What were controlled variables in the basketball experiment?

Starting drop height, ball brand, ball size, bounce surface, and temperature.

In the soap experiment, what is the independent variable?

The type of soap.

In the soap experiment, what is the dependent variable?

The number of bacterial colonies.

What were controlled variables in the soap experiment?

Length of hand washing, temperature of water, growth medium for bacteria, and length of culture incubation.

In the toothpaste experiment, what is the independent variable?

The type of toothpaste.

In the toothpaste experiment, what is the dependent variable?

The whiteness of the teeth.

What were controlled variables in the toothpaste experiment?

Length of brushing time, amount of toothpaste used, and how vigorously the teeth were brushed.

What should you do before making a graph?

Make a data table first.

Which variable goes in the first column of a data table?

The independent variable.

Can a data table have more than one dependent variable?

Yes.

What should a table caption contain?

Table number, title, and a description of the results.

What should a graph's axes have?

Labels with units and evenly spaced numbers.

Which variable changes the dependent variable?

The independent variable.

What should a graph caption contain?

Figure number, title, and a description of the results.

When should you use a scatterplot?

When both variables are quantitative (numbers).

When should you use a line graph?

When both variables are quantitative, especially when the data changes over time.

When should you use a bar graph?

When you have groups or are comparing averages.

When should you use a circle graph?

When comparing qualitative results or parts out of 100%.

What is the relationship between the independent and dependent variables?

The independent variable is changed and the dependent variable is measured in response.

What does it mean for an experiment to be "fair"?

The controlled variables are kept constant so that only the independent variable is changed.

Why is measurement important in an experiment?

The experiment needs measurable results so the data can be analyzed.