Matter

Chemistry - The study of the composition, properties, and changes of matter

  • Matter - Anything with mass and volume

  • Mass - measure of the amount of matter in a substance using a calibrated balance

  • Volume - three-dimensional space occupied by a substance

Matter is composed of Atoms and Molecules

  • may appear smooth and continuous (isn't)

  • composed of atoms, sub-microscopic particles

    • Building blocks of Matter

  • Molecules - two or more atoms joined to each other in specific geometric arrangements

How to classify

  • Phase - solid, liquid, gas

  • Composition - pure substance or mixture

  • Property - Physical and chemical

Solids

  • Constituent particles arranged in a regular, three-dimensional array

  • Alternates positive and negative ions; crystal

  • Partial Positive and Partial negative atoms for covalent compounds

  • Have a definite volume and shape

    • Crystalline Solid - Atoms or molecules are arranged in geometric patterns with long-range, repeating order

      • Ex. Salt and diamond

    • Atoms or molecules occupy specific positions to create a well-ordered 3D figure

    • Amorphous solid - no long-range order

Liquids

  • particles can move about each other while remaining in contact

  • have a definite volume, no definite shape

  • take the shape of a container

Gases

  • separated from each other by large distances and move about randomly in space

  • no definite shape or volume

  • compressible

  • The change from liquid to gas significantly increases the volume of a substance, by a factor of 1000 or more

Pure Substances

  • made up of one type of atom (element) or molecule (compound) that can exist in any phase

  • EX:

    • oxygen in a tank

    • liquid water - H2O

    • solid diamond - carbon

Mixtures

  • made up of two or more substances that can be physically separated into their individual components

    • Ex: Saltwater

  • Two types of mixtures

    • Homogeneous

    • Heterogeneous

Homogenous

  • Through noncombined, it acts like a single substance

  • components are the same throughout the mixture

  • can exist in any phase

    • Gases - air, anesthetics CN R-and02), natural gas

    • Liquids - coffee, Saltwater, whiskey

    • Solids- metal alloys: Brass, cement, plastic

Heterogeneous Mixtures

  • Has visibly separate component parts

  • Different amounts of the mixture components depending on sample location

  • can exist in any phase

    • Gas - smog and smoke

    • Liquid - Salad dressing or other shaken liquids

    • Solid - cookies, dirt, tV set

    • MSC - fruit in smoothie, cereal in milk

How Matter is Described: Physical and Chemical Properties

  • Physical properties can be observed or measured without changing the substance being studied

    • Mass

    • Volume

    • Density

    • melting point

    • Boiling point

    • Phase

    • Color

    • shape

  • Includes changes of State:

    • Vaporizing

    • Condensing

    • Melting

    • Freezing

    • Deposition

    • Sublimation

  • The identity of Substance is unchanged

  • Chemical properties describe how a substance changes and can only be determined by experimentation. A new substance is formed

    • Flammability

    • Ignitability

    • Reactivity

  • Matter has a new identity

  • matter is not created or destroyed

    • Vaporization - Physical

    • Burning - Chemical

Law of Conservation of mass

  • Matter is not created or destroyed in a chemical reaction

  • During Physical and Chemical Changes, the total amount of matter remains constant