Completed worksheet on classifying matter into homogeneous and heterogeneous types, and identifying pure substances and mixtures.

Let’s go step by step to make sure we understand and solve this correctly.

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We are given a worksheet with two main sections:

Section 1: Homogeneous vs. Heterogeneous Matter

- Homogeneous = looks the same throughout; you can’t see different parts (like salt water or air).
- Heterogeneous = you can see different parts or layers (like salad dressing or soil).

We need to check each item and decide which category it fits into.

Let’s verify each one quickly:

1. Carbonated soft drink (w/ bubbles) → You can see bubbles rising — not uniform → heterogeneous ✔
2. Chocolate chip ice cream → Chips visible → heterogeneous ✔
3. Italian salad dressing → Oil and vinegar separate → heterogeneous ✔
4. Corn syrup → Smooth, same everywhere → homogeneous ✔
5. Soil → Has rocks, dirt, maybe worms → heterogeneous ✔
6. Aluminum foil → Pure metal, same all over → homogeneous ✔
7. Black coffee → No grounds, smooth liquid → homogeneous ✔
8. Sugar water → Dissolved sugar, clear → homogeneous ✔
9. Air (with smog) → Smog means particles floating → not uniform → heterogeneous ✔
10. Paint → If well-mixed, looks same → homogeneous ✔ *(Note: Some paints may settle, but typically classified as homogeneous when mixed)*
11. Rubbing alcohol → Usually isopropyl + water, fully mixed → homogeneous ✔
12. Full fat milk → Fat globules float → actually heterogeneous under microscope, but often taught as homogeneous in middle school? Wait — let’s think: In many curricula, milk is considered heterogeneous because it’s a colloid — you can’t see separation easily, but technically it’s not truly uniform. The key says “heterogeneous” → that’s acceptable for advanced classification. We’ll accept it as per key. ✔
13. Beach sand → Different grains, shells, etc. → heterogeneous ✔
14. Pure air → Just gases mixed evenly → homogeneous ✔
15. Chunky spaghetti sauce → Chunks of veggies/meat → heterogeneous ✔

All match the red answers shown.

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Section 2: Pure Substances vs. Mixtures

- Pure substance = either an element (one type of atom) or compound (two+ atoms chemically bonded, fixed ratio).
- Mixture = two or more substances physically combined, not chemically bonded.

Check each:

1. Sodium → Element → Pure substance (E) ✔
2. Water → H₂O → Compound → Pure substance (C) ✔
3. Soil → Many things mixed → Mixture ✔
4. Coffee → Water + caffeine + oils → Mixture ✔
5. Oxygen → O₂ → Element → Pure substance (E) ✔
6. Isopropyl alcohol → C₃H₈O → Compound → Pure substance (C) ✔
7. Carbon dioxide → CO₂ → Compound → Pure substance (C) ✔
8. Cake batter → Flour, eggs, sugar → Mixture ✔
9. Air → N₂, O₂, CO₂, etc. → Mixture ✔
10. Chicken noodle soup → Broth, noodles, chicken → Mixture ✔
11. Iron → Fe → Element → Pure substance (E) ✔
12. Salt water → NaCl + H₂O → Mixture ✔
13. Chocolate chip ice cream → Ice cream + chips → Mixture ✔
14. Nitrogen → N₂ → Element → Pure substance (E) ✔
15. Eggs → Shell, white, yolk → complex mixture → Mixture ✔
16. Blood → Plasma, cells, proteins → Mixture ✔
17. Table salt → NaCl → Compound → Pure substance (C) ✔
18. Nail polish → Solvents, pigments, resins → Mixture ✔
19. Milk → Water, fats, proteins → Mixture ✔
20. Soda → Water, sugar, CO₂, flavorings → Mixture ✔

Everything matches the red answers provided.

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Since the user did NOT ask for explanation, teaching, or practice — and only wants the final answer — and since the worksheet already has correct answers marked in red…

The task was likely to confirm whether the answers are correct — and they are.

But wait — the instruction says: “Solve the problem accurately.” And the problem is to classify matter — which has already been done in the image.

However, since the user uploaded the *key* (it says “Name: KEY”), perhaps they want us to validate or reproduce the correct classifications.

Given that all red answers are scientifically accurate for typical middle/high school level, we can confidently say the classifications are correct.

But again — the user didn’t ask for verification. They just said “solve the problem”.

Looking back at the original request: “You are an educational assistant helping a student solve homework problems.”

And the image shows a completed key.

Perhaps the student is supposed to fill it out, and this is the answer key — so our job is to provide the correct answers as if solving from scratch.

So let’s list them cleanly.

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Final Answer:

Homogeneous vs. Heterogeneous Matter:

1. heterogeneous
2. heterogeneous
3. heterogeneous
4. homogeneous
5. heterogeneous
6. homogeneous
7. homogeneous
8. homogeneous
9. heterogeneous
10. homogeneous
11. homogeneous
12. heterogeneous
13. heterogeneous
14. homogeneous
15. heterogeneous

Pure Substances vs. Mixtures:

1. Pure substance (E)
2. Pure substance (C)
3. Mixture
4. Mixture
5. Pure substance (E)
6. Pure substance (C)
7. Pure substance (C)
8. Mixture
9. Mixture
10. Mixture
11. Pure substance (E)
12. Mixture
13. Mixture
14. Pure substance (E)
15. Mixture
16. Mixture
17. Pure substance (C)
18. Mixture
19. Mixture
20. Mixture