States and Changes of Matter

States of Matter

• Matter exists in three primary states: solid, liquid, and gas.
• Solids have a fixed shape and volume due to tightly packed particles that vibrate.
• Liquids take the shape of their container but have a fixed volume, with particles moving freely but remaining close together.
• Gases have neither a fixed shape nor volume; particles move rapidly in all directions.

Changes of State

• Changes of state are triggered by energy transfer.
• Melting: solid to liquid
• Freezing: liquid to solid
• Evaporation: liquid to gas
• Condensation: gas to liquid
• Sublimation: solid to gas

Melting Point Graphs

• Melting point graphs display temperature changes during heating.
• During phase changes (melting or boiling), temperature remains constant while energy breaks bonds.
• This is shown as a flat section on the graph.

The Periodic Table

• Elements are organized by atomic number on the periodic table.
• Elements in the same column (group) have similar properties.
• Elements in the same row (period) show increasing atomic number.
• Metals are located on the left of the table.
• Nonmetals are located on the right.
• Group 1 (alkali metals) are highly reactive, especially with water.
• Group 7 (halogens) are reactive nonmetals.
• Group 0 (noble gases) are unreactive.

Oxygen (O₂) Case Study

• Oxygen (O₂) is a non-metal gas.
• It's essential for respiration and combustion.
• It's found in water and the atmosphere.

Atoms, Elements, and Compounds

• Atoms are the smallest unit of matter.
• Elements are substances made of one type of atom.
• Compounds form when two or more elements chemically bond.
• Molecules are groups of atoms chemically bonded.

Chemical Bonding

• Compounds are created through chemical bonding.
• Ionic bonding occurs between metals and nonmetals (e.g., NaCl).
• Covalent bonding occurs between nonmetals (e.g., H₂O).
• Chemical formulas represent the ratio of elements in a compound.

Extracting Elements

• Elements can be extracted from compounds through chemical reactions.
• Electrolysis is a method to separate elements (e.g., splitting water).
• Thermal decomposition is another method (e.g., heating copper carbonate).

Mixtures vs Compounds

• Mixtures consist of physically combined substances.
• Components in mixtures retain their properties and can be separated physically (e.g., air).
• Compounds consist of chemically bonded substances.
• Properties of compounds differ from their component elements, and separation requires chemical reactions (e.g., breaking down water).