50+ elements and compounds worksheets for 10th Class on Quizizz ... - Free Printable

Let’s go through each question one by one and figure out the correct answers.

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Question 1: Which of the following represents an element?

An element is a pure substance made of only one type of atom. It cannot be broken down into simpler substances by chemical means.

- A. H₂O → This is water — made of hydrogen and oxygen → compound
- B. CaCO₃ → calcium carbonate → made of calcium, carbon, oxygen → compound
- C. NaCl → sodium chloride (salt) → made of sodium and chlorine → compound
- D. H₂ → this is hydrogen gas — made of only hydrogen atoms → element

✔ Correct answer: D

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Question 2: Which of the following is not a compound?

A compound is made of two or more different elements chemically bonded together.

- A. CO₂ → carbon dioxide → compound
- B. NaCl → salt → compound
- C. Cl → this is just chlorine atom (or diatomic Cl₂ usually, but written as “Cl” here) → it’s an element, not a compound
- D. HCl → hydrochloric acid → compound

✔ Correct answer: C

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Question 3: Salt has a chemical formula of NaCl. Salt is a...

NaCl is made of sodium (Na) and chlorine (Cl) chemically bonded → that’s the definition of a compound.

- A. Compound → ✔ Yes
- B. Element → No, it’s two elements
- C. Mixture → No, mixture is physically mixed, not chemically bonded
- D. None of the Above → Not needed

✔ Correct answer: A

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Question 4: What cannot be broken down into other substances?

This is the definition of an element. Compounds can be broken down into elements. Mixtures can be separated physically. Solids are a state of matter, not a classification of substance.

- A. Compound → can be broken down
- B. Solids → irrelevant category
- C. Element → ✔ Cannot be broken down chemically
- D. Mixture → can be separated

✔ Correct answer: C

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Question 5: What is made up two or more elements that are chemically combined?

That’s the exact definition of a compound.

- A. Mixture → physically combined, not chemically
- B. Element → only one type of atom
- C. Solids → state of matter
- D. Compound → ✔ Correct

✔ Correct answer: D

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Question 6: How many elements are represented in the compound? Na₂CO₃

Break down the formula:

- Na → Sodium → 1 element
- C → Carbon → 1 element
- O → Oxygen → 1 element

Total = 3 different elements

- A. 2 → too few
- B. 1 → no
- C. 3 → ✔ Correct
- D. 4 → too many

✔ Correct answer: C

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Question 7: A combination of substances that are not chemically combined is called

This is the definition of a mixture.

(Though the options aren’t shown, based on standard knowledge, the answer is “Mixture”)

But since the user didn’t provide options for Q7, and we’re to answer only what’s visible, we’ll stop at Q6 for final answer selection.

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Final Answer:
1. D
2. C
3. A
4. C
5. D
6. C