Elements, Compounds, and Mixtures interactive worksheet | Live ... - Free Printable

Let's solve this step by step.

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Part 1: Complete the following sentences using the word bank.

Word Bank:
- two or more
- two or more
- only one
- not chemically joined
- chemically joined

1. An element is made up of only one type of atom.
→ Elements consist of atoms that are all the same (e.g., oxygen atoms in O₂).

2. A compound is made up of two or more different atoms, chemically joined together.
→ Compounds form when different types of atoms bond chemically (e.g., H₂O – hydrogen and oxygen).

3. A mixture is made up of two or more different atoms, not chemically joined together.
→ In mixtures, substances are physically combined but not bonded (e.g., salt and sand).

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Part 2: State whether each statement is true or false.

1. False – Elements can exist as atoms, but also as molecules (e.g., O₂, N₂). So they don't *only* exist as single atoms.

2. False – Compounds can exist as molecules (like H₂O), but also as ionic lattices (like NaCl), which aren't discrete molecules.

3. True – Mixtures can contain atoms, molecules, or both. For example, air is a mixture of O₂ molecules, N₂ molecules, etc.

4. False – Compounds can only be broken down into new substances by chemical reactions, not physically. Physical separation won’t break chemical bonds.

5. True – Elements cannot be broken down into simpler substances by chemical means. That’s what defines an element.

6. False – Mixtures are separated physically, not chemically. Chemical reactions would change the substances, whereas physical methods (like filtration or distillation) separate them without changing their identities.

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Part 3: Students' diagrams of soda water

Soda water is a mixture of carbon dioxide (CO₂) and water (H₂O).
- CO₂ is a molecule: one carbon (black) and two oxygens (gray).
- H₂O is a molecule: one oxygen (gray) and two hydrogens (white).
- Since it's a mixture, the molecules are not chemically bonded to each other — they’re just mixed together.

Let’s evaluate each student:

#### Phillip:
- Shows individual atoms (gray, black, white) scattered.
- Incorrect.
- Error: He shows atoms not joined into molecules. But CO₂ and H₂O exist as molecules. Also, he doesn’t show the correct molecular structures. This suggests he thinks soda water is a mixture of individual atoms, not molecules.

#### Caroline:
- Shows CO₂ molecules (black + two gray) and H₂O molecules (gray + two white).
- Molecules are separate and not bonded.
- Correct.
- She correctly represents the mixture: CO₂ and H₂O molecules coexist without reacting.

#### Roderick:
- Shows molecules where CO₂ and H₂O appear to be chemically bonded (e.g., CO₂ attached to H₂O).
- Incorrect.
- Error: He shows chemical bonding between CO₂ and H₂O, implying a compound formation. But soda water is a physical mixture, not a chemical compound. The molecules remain distinct.

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✔ Final Answers:

#### Complete the sentences:
1. only one
2. two or more, chemically joined
3. two or more, not chemically joined

#### True or False:
1. False
2. False
3. True
4. False
5. True
6. False

#### Student evaluations:
- Phillip: Incorrect. He showed individual atoms instead of molecules. CO₂ and H₂O exist as molecules, not free atoms.
- Caroline: Correct. She accurately represented CO₂ and H₂O molecules mixed together without chemical bonding.
- Roderick: Incorrect. He incorrectly showed CO₂ and H₂O molecules chemically joined, suggesting a compound, but soda water is a physical mixture.

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✔ Summary: Understanding the difference between elements, compounds, and mixtures — and how they're represented at the particle level — is key here.