11/05 Modeling Matter Mid Unit Review

11/05 Modeling Matter Mid Unit Review

Let's review, food scientists!

We are food scientists!

In this unit we helped Good Food Production Inc. test black food coloring to see which color dyes were used to create it.

Multiple Choice

In this unit we are:

• astronomers

• food scientists

• archaeologists

The black food coloring is a mixture of red, blue, and orange dyes. When water molecules rose up, they attracted to the dye molecules and separated the dye molecules into three different layers.

Multiple Choice

Does this picture correctly show the food coloring before the chromatography experiment?

• Yes, it shows that the food coloring is a mixture.

• No, the food coloring is a mixture but this shows the dye colors separated.

• No, this shows a mixture and the food coloring was a pure substance.

The picture on the left correctly shows that the food coloring is a mixture of red dye, orange dye, and blue dye. The picture on the right is incorrect because it shows the dye colors separated (not as a mixture).

Multiple Choice

This picture is wrong! What has to be changed to make this picture of the food coloring before the chromatography test, correct?

• The dye molecules should be mixed up.

• This picture is correct.

The picture on the left correctly shows that the food coloring is a mixture of red dye, orange dye, and blue dye. The picture on the right is incorrect because it shows the dye colors separated (not as a mixture).

Look closely at the list of properties of honey and water.

We learned that different substances have different properties because they have different molecules.

Poll

What is one property about honey and water that is different?

• color

• how quickly each pours

• stickiness

• taste

Multiple Choice

Which statement is true about honey and water?

• Honey has solid molecules and water has liquid molecules.

• Honey and water have different properties because they are made of different molecules.

• Honey and water are both liquids so they are made of the same molecules.

Honey and water are made of different molecules!

• Honey is made of sugar molecules.

• Water is made of water molecules.

Karo syrup and water are made of different molecules. They do not have exactly the same properties.

• They are both clear.

• They are both liquids.

• Karo syrup tastes sweet but water has no taste.

Multiple Choice

Which statement is true about Karo corn syrup and water?

• Since they are both liquids, they are made of the same molecules.

• Since they are made of different molecules, they have different properties.

What is a mixture?

The left picture is a mixture - it shows more than one substance.

A mixture is made of more than one substance that is mixed together.

• The left picture shows a mixture - it is made of four different molecules mixed together.

• The top right picture is not a mixture. It is many pieces of only one substance.

• The bottom right picture is not a mixture. It shows the same molecule six times.

Multiple Choice

Does picture A show a mixture?

• Yes

• No

Picture A does not show a mixture because it shows only water molecules (about 33 of them!)

Multiple Choice

Does picture B show a mixture?

• Yes

• No

Picture B does show a mixture! It shows three molecules (green molecules, blue water molecules, & yellow molecules) all mixed up together.

Multiple Choice

Does picture C show a mixture?

• Yes

• No

Picture C does not show a mixture. It shows three different substances, but these three substances are separated and not mixed up together.

Multiple Choice

Which picture shows a mixture?

• picture 1

• picture 2

• picture 3

Multiple Choice

Why is picture 1 not a mixture? It shows three substances.

• It does show a mixture.

• It shows three substances that are separated. They should be mixed up together.

Sugar, baking soda, and flour look similar. But they are different substances. Each is made of different molecules and has properties that make them different from each other.

Look at the information under each of the powders.

Sugar has no smell, is white, and tastes sweet.

Baking soda has no smell, is white, and tastes bitter.

Flour has no smell, is white, and has no taste.

Multiple Choice

According to the table, how can you tell the difference between sugar, baking soda, and flour?

• look at their color

• smell each of them

• taste each of them

Multiple Choice

If you were able to see the molecules of each of these substances, what would you see?

• All three substances have exactly the same molecules.

• Each of the substances has different molecules.

The chromatography test model

This shows a nanovision model of what the food coloring molecules looked like before the chromatography test, and what the molecules looked like after.

• Look at the before picture. You can see all three dye colors are mixed up together.

• Look at the after picture. You can see the dye molecules were pulled up the strip into separate layers because the dye molecules were attracted to the water molecules.

Multiple Choice

What would happen if the dye molecules were not attracted to water molecules?

• The food coloring mixture would stay as a mixture. It would still be black.

• The food coloring mixture would still separate. Water molecules do not cause it to separate.

Multiple Choice

What happened to the dye colors during the chromatography test?

• The three dye colors separated into three different layers because of the water.

• The dye molecules changed colors.

This shows the correct before and after model.

Multiple Choice

What is wrong about this picture?

• It needs to show the water molecules sticking to each of the dye molecules.

• This picture is correct.

This shows the correct before and after model.

Multiple Choice

What is wrong about this picture?

• The dye molecules should be separated into three different layers.

• This picture is correct.

This shows the correct before and after model.

You can figure out what a substance is based on its properties! Just read the information below each substance.

Water is a clear, thin liquid. It has no smell or taste.

Multiple Choice

Which substance is water?

• Substance M

• Substance N

• Substance O

• Substance P

Substance M is water because look - it has no smell, is thin, and is clear.

Substance N also has no smell, but it is thick and yellow. Water is not thick and yellow. :)

This is rubbing alcohol. It is clear. It has a strong, harsh smell. It is thin and is used to clean.

Multiple Choice

Which substance is rubbing alcohol, a clear & strong smelling chemical used for cleaning?

• Substance M

• Substance N

• Substance O

• Substance P

Substance O is rubbing alcohol because it is clear, thin, and has a harsh smell.

It can't be substance M, because substance M has no smell!

Corn syrup is a thick, clear liquid. It is a syrup so it tastes sweet. Corn syrup is used in cooking and baking.

Multiple Choice

Corn syrup is a thick, clear syrup that is used in cooking. Which substance is corn syrup?

• Substance M

• Substance N

• Substance O

• Substance P

Substance N is corn syrup because it is thick and yellow. It also has no smell.

States of Matter

• A shows a liquid.

• B shows a gas.

• C shows a solid.

Multiple Choice

Which picture shows molecules of a gas like air?

• A

• B

• C

States of Matter

• A shows a liquid.

• B shows a gas.

• C shows a solid.

Multiple Choice

Which picture shows molecules of a liquid like water?

• A

• B

• C

States of Matter

• A shows a liquid.

• B shows a gas.

• C shows a solid.

Multiple Choice

Which state of matter has molecules that move the fastest?

• molecules in water

• molecules in air

• molecules in paper

• Molecules in a gas (B) like air move the fastest.

• Molecules in a solid like paper (C) move the slowest.

Poll

Which topics would you like more help reviewing before the test?

• solids, liquids, gases

• mixtures

• what happens during a chromatography test

• how to identify a substance based on its properties

• None of these, I feel 100% prepared for the test.