Table of contents

1. Intro to General Chemistry3h 48m
2. Atoms & Elements4h 16m
3. Chemical Reactions4h 10m
4. BONUS: Lab Techniques and Procedures1h 38m
5. BONUS: Mathematical Operations and Functions48m
6. Chemical Quantities & Aqueous Reactions3h 53m
7. Gases3h 49m
8. Thermochemistry2h 37m
9. Quantum Mechanics2h 58m
10. Periodic Properties of the Elements3h 9m
11. Bonding & Molecular Structure3h 29m
12. Molecular Shapes & Valence Bond Theory1h 57m
13. Liquids, Solids & Intermolecular Forces2h 23m
14. Solutions3h 1m
15. Chemical Kinetics2h 53m
16. Chemical Equilibrium2h 29m
17. Acid and Base Equilibrium5h 1m
18. Aqueous Equilibrium4h 47m
19. Chemical Thermodynamics1h 50m
20. Electrochemistry2h 42m
21. Nuclear Chemistry2h 36m
22. Organic Chemistry5h 7m
23. Chemistry of the Nonmetals2h 39m
24. Transition Metals and Coordination Compounds3h 16m

1. Intro to General Chemistry

Classification of Matter

General Chemistry

1. Intro to General Chemistry

Classification of Matter

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Multiple Choice

Brass is a combination of a number of elements, and its exact composition can vary. Based on this information, brass is best classified as which of the following?

A pure substance

An element

A compound

A mixture

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Verified step by step guidance

Understand the definitions of the terms: An element is a pure substance consisting of only one type of atom; a compound is a pure substance made of two or more elements chemically combined in a fixed ratio; a mixture consists of two or more substances physically combined, where each retains its own properties.

Recognize that brass is made by combining copper and zinc, which are elements, but they are not chemically bonded in a fixed ratio; instead, they are physically mixed.

Since the composition of brass can vary and it is not a single pure substance with a fixed chemical formula, it does not fit the definition of a compound or an element.

Therefore, brass is best classified as a mixture because it is a physical combination of different elements without a fixed composition.

Conclude that the correct classification of brass is a mixture, as it retains the properties of its constituent elements and its composition can vary.