# Lesson: Mixtures - Homogeneous, Heterogeneous

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### Lesson Objective

SWBAT identify whether a mixture is homogeneous, heterogeneous, or pure by labeling the different examples SWBAT write one-sentence main ideas in science passages

### Lesson Plan

1. I.                    First Impressions                                                                                                                    (≈ 1 minute)
1. Ensures the line is silent, greet students at the door, shake their hand
“Every day, this is how you will come in: line up silently by the door, shake my hand, and find your seat silently. These will be your assigned seats, unless otherwise told so. You will take out a pen and begin on the Do Now. Everything else needs to go directly under your desk”
2. Directs each student to his/her seat
3. Seats – “Do Now” ½ sheet with exit ticket on the back
4. Same person will do attendance (attendance clipboard will be at the same place every day, and students will just have to write a check next to each person’s name, an “ABS” if they are absent)
2. II.                  Do Now                                                                                                                                        (≈ 5 minutes)

What are 2 examples of a physical change?

What are 2 indicators of a chemical change?

1. During the Do Now, I will collect homework (note which students did not do/finish & have them write me a note as to why they did not have their homework)
2. I will also have to pass back papers
3. Students will take out a red/colored pen
4. Students will correct their own paper
5. I will call on students to answer this question
6. Students will slide up their sheets to the top of their table
7. III.                Introduction to Main Idea                                                                                                   (≈ 8 minutes)
1. Hook: Sometimes people ramble a lot. However, you try to get the what of all their talking?

i.      Main idea; their main point

1. I really enjoy reading science passages, but sometimes they may be a little dry.
2. We’re going to practice reading some science passages so we can get ready for the ACT science
3. Students will take out a loose-leaf sheet of paper
4. Students will label this Main Idea; write #1.
5. Look at the worksheet:

i.      Someone read out the first paragraph

ii.      Main idea: mixtures are at least 1 compound/element added to another

1. IV.                Guided Practice to Main Idea                                                                                            (≈ 8 minutes)
1. I will call on another student to read another paragraph
2. I will call on another student to give me the main idea of the paragraph
3. We will discuss – see if anyone wants to addd/tweak
4. Students will write down #2, and then write their own main idea
2. V.                  Independent Practice to Main Idea                                                                                 (≈ 8 minutes)
1. Students will finish reading the article
2. Students will have a list of #1-11 on their paper
3. I will collect their loose leaf sheets of paper

i.      Ensure that each student is only writing down 1 sentence

ii.      Summarizing/giving the main idea of the paragraph

iii.      I want to go over paragraphs #3 & #4

1. VI.                Introduction to Mixtures                                                                                                     (≈ 8 minutes)
1. Hook: 2 beakers: 1 has dirt settled on the bottom; the other beaker is a colored water

i.      What do you see in beaker 1? Dirt

ii.      Where do you see it in relation to the water? On the bottom

iii.      What do you see in beaker 2? The water is colored (barium chromate that can be separated in a centrifuge)

iv.      Where do you see it in relation to the water? Everywhere – it is even

1. Students will take out their chemistry notebooks (for their notes)
2. We will be talking about mixtures today
3. I will call on people to give me a definition of mixture, homogeneous mixture, heterogeneous mixture, and pure substance

i.      Mixture: blend of 2 or more kinds of matter, each of which retains its own identity and properties

ii.      Homogeneous: mixture that is uniform in composition (solutions)

iii.      Heterogeneous: mixture that is not uniform throughout

iv.      Pure substances: homogeneous, and every sample has exactly same characteristics, exactly the same composition

1. In our hook, which beaker was homogeneous mixture? Which one was the heterogeneous mixture?
2. I will go over these examples
3. VII.              Guided Practice to Mixtures                                                                                              (≈ 15 minutes)
1. Students will close their notebooks, and put them away
2. I will have a few examples of heterogeneous & homogeneous mixtures, and I will have a few students identify these mixtures
3. Students will then call on each other to agree or disagree with their teammates

i.      Kool-Aid: homogeneous mixture

ii.      Honey: homogeneous mixture

iii.      Salsa: heterogeneous mixture

iv.      Chicken soup: heterogeneous mixture

v.      Tea: homogeneous mixture

vi.      Just water: pure! Tricky…

1. VIII.            Independent Practice to Mixtures                                                                                   (≈ 20 minutes)
1. Exit ticket
2. Students will be given a few more on a worksheet, and identify if the example is a homogeneous mixture or a heterogeneous mixture (and write why they think that is – is it evenly mixed? Or is it not even?)

i.      Coffee – homogeneous; evenly mixed

ii.      Salt water – homogeneous; evenly mixed

iii.      Sandy water – heterogeneous; not evenly mixed

iv.      Vinegar combined with oil – heterogeneous; unable to mix

v.      Extra virgin olive oil – homogeneous; evenly mixed

vi.      Jello – homogeneous; evenly mixed

vii.      Trail mix – heterogeneous; can separate each one

1. IX.                Closing                                                                                                                                         (≈ 8 minutes)
1. Students will have a brief exit ticket on the back of their Do Now: identify whether or not the mixture is considered a homogeneous mixture, heterogeneous mixture, or if it is pure
2. Students will put everything away except for their Do Now and a pen/pencil
3. Students will have 5 minutes to finish their exit ticket

i.      Gatorade (salt water) – homogeneous

ii.      Air we breathe (combination of oxygen and nitrogen) – homogeneous

iii.      Marbles in water – heterogeneous

iv.      Raisin bran cereal – heterogeneous; could pick out the raisins

v.      Gold, without anything else in it – pure

1. On the board:

i.      Homework – Given an example, how would you test whether or not it is a homogeneous mixture, a heterogeneous mixture, or a pure mixture? What questions would you ask?

1. Close – take out binder, put in today’s work and write down homework

i.      Put binder back in backpack

ii.      Put pencils/everything else back in backpack

iii.      Make sure there’s no trash left. (leave it better than you found it) If there is, pick it up, keep it, and throw it in the trashcan as you leave

iv.      Silent exit

v.      Whichever group is ready first (cleaned up – no trash, packed, silent, and have eyes) will be dismissed first

vi.      Dismiss one group

vii.      If someone does not do it correctly, group comes back and tries again

### Lesson Resources

 No resources at this time.