Chemistry Worksheet: Matter #1 | PDF | Chemical Substances | Mixture - Free Printable

Let's go through each question on the Chemistry Worksheet: Matter #1 and solve them step by step with explanations.

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1. A mixture (is/is not) a chemical combining of substances.

✔ Answer: is not

🔹 Explanation: A mixture is a physical combination of substances, not a chemical one. The components retain their individual properties and can be separated by physical means.

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2. In a compound the (atoms/molecules) are (chemically/physically) combined so that the elements that make up the compound (retain/lose) their identities and (do/do not) take on a new set of properties.

✔ Answer:
- atoms
- chemically
- lose
- do

🔹 Explanation: In a compound, atoms of different elements are chemically bonded together in fixed ratios. They lose their original identities and form a substance with entirely new properties.

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3. The smallest identifiable unit of a compound is a(n) ___________, which is made up of ___________ which are chemically bonded.

✔ Answer:
- molecule
- atoms

🔹 Explanation: A molecule is the smallest unit of a compound that retains its chemical properties. It consists of two or more atoms chemically bonded together.

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4. True or False: A mixture is always made up of a combination of elements.

✔ Answer: False

🔹 Explanation: A mixture can consist of elements, compounds, or both. For example, saltwater is a mixture of water (a compound) and salt (a compound). So mixtures don't have to be made only of elements.

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5. In a mixture, the substances (lose/retain) their identities.

✔ Answer: retain

🔹 Explanation: In a mixture, the substances keep their own chemical identities. For instance, in saltwater, you can still separate salt and water individually.

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**6. In a mixture the substances involved (can/cannot) be separated by a simple physical process.

In a compound the elements involved (can/cannot) be separated by a simple physical process because the elements are (physically combined/chemically bonded).**

✔ Answer:
- can
- cannot
- chemically bonded

🔹 Explanation: Mixtures can be separated physically (e.g., filtration, evaporation). Compounds require chemical reactions to break down because the elements are chemically bonded.

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7. True or False: An element can be broken down into a simpler substance.

✔ Answer: False

🔹 Explanation: Elements are pure substances made of only one type of atom and cannot be broken down into simpler substances by chemical means.

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8. The smallest identifiable unit of an element is a(n) ___________.

✔ Answer: atom

🔹 Explanation: An atom is the smallest unit of an element that retains the chemical properties of that element.

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9. From the following list of substances, circle the ones that are elements:

List:
- silver ✔
- carbon dioxide ✘ (compound)
- wood alcohol ✘ (compound, ethanol)
- chromium ✔
- water ✘ (compound)
- hydrogen ✔
- carbon ✔
- nitrogen ✔
- oxygen ✔
- gold ✔
- sugar ✘ (compound)
- salt ✘ (compound, NaCl)
- air ✘ (mixture)
- sulfur ✔
- magnesium ✔
- nickel ✔

✔ Elements:
silver, chromium, hydrogen, carbon, nitrogen, oxygen, gold, sulfur, magnesium, nickel

🔹 Explanation: Elements are pure substances made of only one type of atom. Compounds and mixtures are not elements.

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10. Explain how to separate the sugar and water in a solution of sugar and water.

✔ Answer: Use evaporation.

🔹 Explanation: Heat the solution gently. Water will evaporate (turn into vapor), leaving behind solid sugar. This works because sugar does not evaporate at the same temperature as water.

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11. How would you separate a mixture of alcohol and water?

✔ Answer: Use fractional distillation.

🔹 Explanation: Alcohol (ethanol) and water have different boiling points. Ethanol boils at around 78°C, while water boils at 100°C. By heating the mixture, ethanol vaporizes first and can be collected separately by condensation.

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12. How would you separate sand and water?

✔ Answer: Use filtration.

🔹 Explanation: Sand is insoluble in water. Pour the mixture through filter paper. Water passes through, but sand remains on the filter paper.

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✔ Final Answers Summary:

1. is not
2. atoms, chemically, lose, do
3. molecule, atoms
4. False
5. retain
6. can, cannot, chemically bonded
7. False
8. atom
9. silver, chromium, hydrogen, carbon, nitrogen, oxygen, gold, sulfur, magnesium, nickel
10. Evaporate the water; sugar remains.
11. Use fractional distillation based on different boiling points.
12. Use filtration.

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