Science Investigation September 2, 2011

Ms. SmithMrs. Malone

:

DO NOW:

1.Pick up your handouts.

2.Put the “M&M Reading” homework on the corner of your desk.

3.Complete the “Lab Safety Matching Cards” handout.

Well-Defined Questions

Create a hypothesis for the following scientific question.

Question: Does vinegar cause M&M colors to dissolve faster than water?

A hypothesis is an educated guess about how

things work.

Hypothesis

Question: “Do some M&M colors dissolve faster in water than others?”

Write your hypothesis behind the “Hypothesis” tab in your foldable.

I predict…

Hypothesis

• IF the M&M has a darker color, THEN it will dissolve faster.

• IF the M&M has a lighter color, THEN it will dissolve faster.

Hypothesis

Behind the “Materials” tab in your foldable, list all of the materials that you will be using in the M&M Investigation lab.

Materials:• White paper• Different colored M&Ms • Water• Pipette• Petri dish• Beaker• Marker• Timer • Paper towels

Materials

• These changing quantities are called VARIABLES.

• An experiment has 3 kinds of variables: independent (manipulated), dependent

(responding) and controlled (constants)

Variables

• Variable that is purposely changed or manipulated• a fair test has only one independent variable.

Example: Does the amount of fertilizer affect plant growth? The amount of fertilizer is the independent variable because the scientist has control over how much fertilizer is used in the experiment.

Independent Variable

Suppose that you wonder whether you can run a marathon faster when you eat pasta the night before or when you drink coffee the morning of the race. Your hunch is that loading up on pasta will give you the energy to run faster the next day. The independent variable is the consumption of pasta, and the dependent variable is how fast you run the race.

Now, if you eat several plates of spaghetti the night before you race, but then get up the next morning and drink two cups of coffee before you head to the start line, your experiment is useless.

Why is it useless? By drinking the coffee, you introduce a second independent variable, so you will not know whether the faster race time is due to the pasta or the coffee.

Independent Variable

What is the independent variable in your M&M investigation?

Independent Variable

Independent Variable:

M&M Color

Why is M&M color the independent variable?

Independent Variable

• what is measured in the experiment

Example:Does the amount of fertilizer affect plant growth?

Dependent Variable

What is the dependent variable

in your M&M investigation?

Dependent Variable

Answer: How fast the M&M colors dissolve.

Dependent Variable

• The variables that are not changed are called controlled variables. (constants)

Example:Does the amount of fertilizer affect plant growth?

Independent variable: amount of fertilizerDependent variable: plant growth

Controlled variables: same type of plant, same pot size, same amount of water, same amount of sunlight

Constants

• A graph is a chart or drawing that shows the relationship between changing things

• Can you name some common graph types?• Graphs must include a title and labels on the x

and y axis.

Why will we use a bar graph in our M&M investigation?

Graphs

TITLE

Y-Axis

Dependent Variable

X-Axis Independent Variable

Bar Graph Example

D = dependent variableR = responding variableY = graph information on the Y-axis (vertical, up and down)

M = manipulated variable I = independent variableX = graph information on the X-axis (horizontal, side to side)

DRY MIX