Study Guide: Introduction to Chemistry – Chapter 3 Concepts Part 1

Q1. Can you define matter?

• Matter: Anything that has mass and occupies space.

• Consider the two essential properties: mass and volume.

Q2. Can you define the three states of matter?

• Solid: Definite shape and volume.

• Liquid: Definite volume, no definite shape.

• Gas: No definite shape or volume.

Q3. Can you identify the three states of matter from description or molecular view diagrams?

• Solids: Particles closely packed, fixed positions.

• Liquids: Particles close but can move past each other.

• Gases: Particles far apart, move freely.

Q4. Can you define and identify a pure substance?

• Pure Substance: Matter with a fixed composition and distinct properties (elements or compounds).

Q5. Can you define and identify a mixture?

• Mixture: A combination of two or more substances that are not chemically bonded. (e.g., salt water, air) and how they differ from pure substances.)Identify whether the composition is variable and if the components can be separated physically.

Q6. Can you explain the difference between a pure substance and a mixture?

• Pure substances have a fixed composition; mixtures have variable composition.

• Pure substances cannot be separated by physical means; mixtures can.

Q7. Can you define and identify an element?

This question is about the simplest form of matter with unique properties.

Key Terms:

• Element: A substance that cannot be broken down into simpler substances by chemical means. (e.g., oxygen, iron) and how they appear on the periodic table.

• Identify whether a given substance is made of only one type of atom.

Q8. Can you define and identify a compound?

• Compound: A substance made of two or more elements chemically bonded in a fixed ratio.

Q9. Can you explain the difference between an element and a compound?

• Elements consist of one type of atom; compounds consist of two or more types of atoms chemically bonded.

• Elements cannot be broken down by chemical means; compounds can.

Q10. Can you define and identify a homogeneous mixture?

• Homogeneous Mixture: A mixture with the same composition throughout (also called a solution).

• Think of examples (e.g., salt water, air) and how they appear uniform.

• Identify whether a given mixture looks the same throughout.

Q11. Can you define and identify a heterogeneous mixture?

• Heterogeneous Mixture: A mixture with visibly different parts or phases.

• Think of examples (e.g., salad, sand in water) and how they have distinct parts.

• Identify whether a given mixture has visible differences in composition.

Q12. Can you explain the difference between a homogeneous mixture and a heterogeneous mixture?

This question asks you to compare mixtures with uniform and non-uniform composition.

• Homogeneous mixtures are uniform throughout; heterogeneous mixtures are not.

• Examples help clarify the distinction.