Matter and Energy Basics

Matter

• Anything with mass and volume
• Law of Conservation of Matter: Matter is neither created nor destroyed

Energy

• 9 forms of energy
• Law of Conservation of Energy: Energy is not created or destroyed, just converted from one form to another
• Kinetic Energy: Energy of motion
• Potential Energy: Stored energy
• Mechanical Energy: Combination of potential and kinetic energy
• Sound Energy: Energy that travels as vibrations
• Chemical Energy: Energy stored in chemical bonds
  • Released when bonds form
  • Absorbed when bonds are broken
• Light Energy: Electromagnetic radiation
• Heat Energy: Energy transferred due to temperature differences
  • Solar Energy: Energy from the sun
• Nuclear Energy: Energy released from the nucleus of an atom through fission or fusion
  • Formula: E=mc2 (energy equals mass times the speed of light squared)
• Electrical Energy: Energy associated with the movement of electrons

Substance

• Matter made up of only one type of matter, always homogeneous

Elements

• Found on the periodic table
• Building blocks of all matter
• 118 elements
• Majority are metals
  • Gases: Noble Gases (Group 18)
    • Examples: H2, O2, F2, Cl2, N2
  • Liquids:
    • Liquid Metal: Mercury (Hg)
    • Liquid Non-metal: Bromine (Br)
  • Solids: All other elements

Compounds

• Two or more elements chemically combined
• Acquire entirely new chemical and physical properties
• Law of Definite Proportions: Every sample of the same compound has the same ratio of elements
• Law of Multiple Proportions: Same elements can combine to form multiple different compounds
• Examples: CO (Carbon Monoxide) and CO2 (Carbon Dioxide)

Mixture

• Two or more substances physically combined
• Each substance retains its original properties

Homogeneous Mixture

• Uniform throughout
• Solute is dissolved
• Also known as solutions
• Examples: Saltwater, sugar water, air
• Alloys: Solid solutions
  • Examples: Bronze, Steel, Brass

Heterogeneous Mixture

• Non-uniform throughout
• Composition varies depending on the sample location
• Examples: Sand in water, salad dressing, soil, blood, milk

Properties of Matter

Intensive Properties

• Do not change with the size of the sample
• Examples: Density, pH, color, hardness, luster (shine), malleability

Extensive Properties

• Change with the size of the sample
• Examples: Mass, Volume, Weight, Surface area, Amount of Matter
• Dependent on gravity