C165 Integrated Physical Sciences - Chemistry

Section 2: Lesson 1 - Structure of Atoms

Key Concepts

• Matter: Anything that takes up space and has mass, composed of atoms.
• Mass: Measure of matter, not the same as weight. SI unit: kilograms (kg).
• Atom: Basic building block of matter, cannot be seen under a microscope.
• Nucleus: Center of an atom, contains protons and neutrons.
• Protons: Positively charged, located in the nucleus.
• Neutrons: Neutral charge, located in the nucleus.
• Electrons: Negatively charged, located outside the nucleus in shells; very little mass.
• Electron clouds: Region where electrons are found, location uncertain.
• Valence electrons: Outermost electrons involved in chemical bonding and reactions.

Subatomic Particles Overview

Important Concepts

• Valence Electrons: Key in chemical bonding and reactions.
• Atomic Number: Number of protons; determines element identity. Changing protons changes the atomic number.
• Bond Formation: Involves sharing or transferring valence electrons; does not change atom identity as protons remain unchanged.

Section 2: Lesson 2 - Elements, Compounds, and Mixtures

Definitions

• Element: Substance consisting of atoms with the same number of protons.
• Compound: Substance composed of two or more elements chemically combined.
• Organic Compound: Contains carbon, typically found in living systems.
• Inorganic Compound: Does not contain carbon-hydrogen bonds.
• Chemical Bond: Force holding atoms together in a molecule.
• Molecule: Two or more atoms bonded together.
• Pure Substance: Material with consistent composition.
• Mixture: Combination of two or more substances not chemically bonded.
• Homogeneous Mixture: Evenly mixed, uniform composition.
• Heterogeneous Mixture: Unevenly mixed, variable composition.

Types of Substances

Section 2: Lesson 3 - Solids, Liquids, and Gases

States of Matter

• Solid: Definite shape and volume.
• Liquid: Definite volume, shape of its container.
• Gas: No definite shape or volume.

Properties

• Macroscopic Properties: Observable characteristics.
• Microscopic Properties: Particle-level characteristics.

Characteristics by State