Matter: Anything that has mass and occupies volume. Key properties include mass, volume, and density. Units for volume include L, dm3, mL, and cm3.

States of Matter: Solid, liquid, and gas, each with distinct particle arrangements and properties.

Classification of Matter:

• Pure Substances: Elements (one type of atom) and compounds (two or more types of atoms chemically bonded).

• Mixtures:

  • Homogeneous (solutions): Uniform composition throughout (e.g., air, alloys).

  • Heterogeneous: Non-uniform composition (e.g., suspensions, salad).

Elements:

• Monatomic: Single atoms (e.g., He).

• Polyatomic: Several like atoms bonded (e.g., O2, P4).

• Allotropes: Different forms of the same element in the same state (e.g., O2 vs. O3, graphite vs. diamond).

Compounds:

• Contain two or more different atoms chemically bonded.

• Properties differ from constituent elements.

• Can only be separated by chemical means.

Mixtures:

• Not chemically bonded; can be separated by physical means.

• Separation methods:

  • Sorting

  • Filtration

  • Magnetism

  • Chromatography

  • Density

  • Distillation

Properties of Matter:

• Chemical Properties: Describe how substances react (e.g., reactivity, flammability).

• Physical Properties: Observed without changing substance identity (e.g., melting point, density).

• Extensive Properties: Depend on amount (e.g., mass, volume).

• Intensive Properties: Independent of amount (e.g., density, boiling point).

Density: Ratio of mass to volume. d=mV

• Units: g/cm3 (solids), g/mL (liquids).

• Density is nearly constant for a given substance.

Law of Conservation of Energy: Energy cannot be created or destroyed, only transformed.

• Endothermic: System absorbs heat (e.g., boiling, melting).

• Exothermic: System releases heat (e.g., freezing, combustion).

Mole Concept:

• 1 mole = 6.02 × 1023 particles (Avogadro's number).

• Mole relates mass, number of particles, and volume for substances.

• For any element, 1 mole has a mass (in grams) equal to its atomic mass from the periodic table.

Sample Calculations:

• Finding mass, percent composition, and number of moles or atoms using the relationships:

  • n=mM (moles = mass / molar mass)

  • N=n×6.02×10^23 (number of particles = moles × Avogadro's number)

Visual Aids: Diagrams illustrate states of matter, changes of state, and classification of matter (element, compound, mixture).