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What is Chemistry. Chemistry ‑ the study of matter and the changes matter undergoes. Matter ‑ something that has mass and takes up space (has a volume). States of Matter. Law of Conservation of Mass & Energy-

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What is chemistry
What is Chemistry

  • Chemistry ‑ the study of matter and the changes matter undergoes.

  • Matter ‑ something that has mass and takes up space (has a volume).


States of matter
States of Matter

  • Law of Conservation of Mass & Energy-

    • Matter can never be created nor destroyed; neither gained nor lost. It must be conserved.



Characteristics of matter
Characteristics of Matter

Chemical Properties

  • Ability for a substance to undergo a chemical change (new stuff)

  • Examples.

    • Ability to burn

    • Ability to rust

    • Ability to sour


Physical properties
Physical Properties

Physical Properties observed or measured

without altering makeup of substance (still the same

stuff)

  • Examples

    • mass

    • weight

    • volume

    • color

    • solubility

    • luster

    • melting point

    • boiling point


Intensive vs extensive properties

Extensive

depends on amount of matter present

Examples

mass

weight

volume

Intensive:

doesn't depend on amount present

Examples

color

solubility

luster

melting point

boiling point

Intensive vs. Extensive Properties



Classification of matter1
Classification of Matter

Pure Substances

  • Elements- 118 on Periodic Table organized according to properties.

  • Named after famous scientists, countries, states, and planets

  • Abbreviation (Element symbols) begin with first letter capitalized.

  • Examples

    • Al - aluminum

    • O - oxygen

    • Hg - mercury (Latin hydrargyum)

    • Au - gold (Latin Aurum)

    • Cl - chlorine


Classification of matter2
Classification of Matter

Compounds: element combined in a

chemical rxn (reaction).

  • Can not be physically separated.

  • Many have both common names and scientific names.

  • Abbreviations (Chemical formulas) use element symbols

  • Examples

    • NaCl sodium chloride salt

    • NaOH sodium hydroxide Drano

    • NaHCO3 sodium bicarbonate Baking Soda

    • H2O Dihydrogen monoxide Water


Separation
Separation

Separation by Physical Means

  • Filtration

  • Evaporation

  • Distillation

  • Chromatography

Pure Substances

Mixtures

Separation


Classification of matter3
Classification of Matter

Mixtures: can be physically separated

  • Methods of separation

    • Filtration – solid/liquid

    • Evaporation or crystallization – dissolved substance

    • Distillation – purifies a liquid or separates 2 liquids, based on different boiling points

    • Chromatography – separates a solution by allowing it to flow along a stationary substance (liquid, gas, paper).


Classification of matter4
Classification of Matter

Types of Mixtures

Homogeneous - the same composition throughout

  • Examples:

    • Pure air or Solutions (Kool-aid)

    • Alloys – Brass, Steel, Silverware

      Heterogeneous- varying composition throughout

  • Examples:

    • Chocolate Chip Cookies

    • River water


Types of changes
Types of Changes

Substances can undergo three types of

changes:

  • Physical

  • Chemical

  • Nuclear


Physical
Physical

  • Physical- though appearance (color, shape) may change, the mass will still be the same since the molecules remain the same

  • Examples:

    • Bending

    • Tearing

    • Melting


Separation cont d
Separation Cont’d

Compounds can only be separated chemically into elements

Elements

Compounds

Separation


Chemical
Chemical

  • Chemical- (Rxn) the structure of the substance changes. The new substance possesses different chemical and physical properties

  • Examples:

    • Burning

    • Molding

    • Souring


Parts of chemical rxn
Parts of Chemical RXN

2 parts to a Chemical Rxn

  • Reactants  Products

  • Starting substances yields new substances with new properties.

    Three Indicators of Chemical Rxn’s

  • Formation of heat and/or light (energy)

  • Formation of a new gas (bubbles or fizzes)

  • Formation of a precipitate (solid formed for two solutions)


Nuclear
Nuclear

  • the structure of the nucleus changes. The energy involved is 6 to 8 times the Magnitude of a chemical or physical change.



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