Compounds & Mixtures Lesson Overview

Compounds & Mixtures Lesson Overview

Benchmark Standards: SC.8.P.8.4, SC.8.P.8.5, SC.8.P.8.8, SC.8.P.8.9

Open Ended

Warm-Up: How would you describe to a friend how atoms are made into compounds? Use an example.

​Look at the image above. Turn and Talk to your partner and discuss why these two images are an example of a compound?

Compounds

Multiple Choice

Are compounds considered a pure substance? Why?

• Yes, they are considered a pure substance because they are made up of two or more elements. Elements are pure substances.

• No, they are not considered a pure substance because they are a mixture of two elements. If there is a mixture, this cannot be considered a pure substances.

Because a compound is made up of more than 2 elements, a model of a compound is composed of two or more colors.

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What does a compound look like?

Multiple Choice

Which color in the compounds shown in the image are hydrogen atoms?

• red

• gray

• black

• white

Multiple Choice

Which color in the compounds shown in the image is a carbon atom?

• red

• black

• blue

• white

Multiple Choice

How can you represent different compounds using beads?

• by putting similar colors and similar sizes of beads together.

• by putting different colors and different sizes of beads

• by putting all the beads together and make a pile

• by using only one color of beads

Multiple Choice

Which option is NOT an example of a pure substance?

• a liquid having a cloudy color

• a liquid having a high viscosity (restriction of flow)

• a homogeneous mixture of magnets

• a heterogeneous mixture of magnets and rocks

Open Ended

Why would a scientist use litmus paper during an investigation?

Categorize

Options (6)

Have a pH of <7

Are corrosive in nature

Taste sour

Have a pH of >7

Are slippery

Taste bitter

Organize these options into the right categories

Acids

Bases

Multiple Choice

If Ms. Morales was testing the pH levels of different solutions, what color would a base turn on litmus paper?

• blue

• red

• green

Multiple Choice

If Ms. Morales was testing the pH levels of an acidic solution and she spills an alkaline solution on the litmus paper. What would happen?

• the litmus paper would turn blue

• the litmus paper would turn red

• the litmus paper would be neutral

• the litmus paper would burn

Multiple Choice

If Ms. Morales was testing the pH levels of different solutions, what color would an acid turn on litmus paper?

• blue

• green

• yellow

• red

Rachel is given 50 grams each of three different white powders that look very similar. She is told that each of these powders is commonly used in cooking. Without tasting any of them, she is asked to try to identify them. She is told the amounts of sugar and salt that can each be dissolved in 100 mL of water.

Rachel adds all 50 grams of one powder to 100 mL of water and stirs it for a while. Afterwards, she has a clear liquid with no trace of the powder in it.

What would you highlight as important information to answer this question?

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Using testing strategies to help you with long paragraphs.

Dry ice is made up of solid carbon dioxide.

When you place dry ice in hot water it becomes a gas.

​This is called sublimation.

What is dry ice?

Turn and Talk:
What is sublimation? How does this relate to dry ice?

Sublimation is the process where a solid turns into a gas.

Multiple Choice

If dry ice changes from a solid to a gas, what happens to the speed of the molecules?

• the molecule get slower because it stays a solid

• the molecules get faster because it becomes a gas

• the molecules stay the same because nothing changes

• the molecules get slower because they are slow

Match

Match the following

Compound

Element

Mixture

• Compound

• Element

• Mixture

Open Ended

Describe what was helpful or challenging during today's lesson.