Physical Science: States of Matter

States of Matter

• Four main states of matter:
  • Solid
  • Liquid
  • Gas
  • Plasma (high-energy state, not commonly encountered in everyday life)
• Characteristics of each state:
  • Solid: fixed shape and volume, particles closely packed
  • Liquid: takes shape of container, particles close but able to move past each other
  • Gas: takes shape and volume of container, particles widely spaced and freely moving

Types of Matter

• Elements: simplest form of matter, cannot be broken down into simpler substances (e.g. hydrogen, oxygen, carbon)
• Compounds: composed of two or more different elements, chemically bonded together (e.g. water, salt, sugar)
• Mixtures: combination of two or more substances, not chemically bonded (e.g. air, soil, blood)

Changes of State

• Phase transitions:
  • Melting: solid to liquid
  • Freezing: liquid to solid
  • Evaporation: liquid to gas
  • Condensation: gas to liquid
  • Sublimation: solid to gas (e.g. dry ice)
  • Deposition: gas to solid (e.g. frost)
• Factors affecting changes of state:
  • Temperature
  • Pressure
  • Surface area

Chemical Properties

• Reactivity: ability of a substance to undergo a chemical reaction
• Flammability: ability of a substance to catch fire
• Corrosivity: ability of a substance to wear away or destroy other materials
• Toxicity: ability of a substance to cause harm or poison living organisms

Physical Properties

• Color
• Odor
• Texture
• Density
• Solubility
• Boiling and melting points
• Viscosity
• Conductivity (heat, electricity, or sound)