Chemistry Unit 1

Chemistry - The study of matter, props, and the change it goes through

Matter - Anything that has mass (grams) and has volume (mL)

Density = mass/volume

Physical Change

  • A change of matter from 1 form to another without a change in chemical props.

  • Symbols will still be the same

  • Words to indicate this are:

    • boil, dissolve, melt, condense, break, split, grind, cut or crush

Chemical Change

  • Matter’s formula is different after chem change

  • Turns into an entirely new substances with different properties.

  • Words to indicate this are:

    • burn, react, rot, rust, decompose, ferment, cook, explode, corrode

Physical Props.

  • quality of substance be measured/observed without changing

  • EX of this: color, melting point, boiling point, mass, vol., density, luster, odor

Chemical Props

  • Substances ability undergo changes transform it into different substances

  • Evidence of a chemical change -

    • Color change, formation of bubbles, temp. change, release/absorption of E, formation of precipitation (solid)

Mixture - Combination of 2 substances that are NOT chemically bonded (a formula can’t be written for it.)

Pure Substance - A formula can be written for it and is either compound or an element

Diff. Types of Mixtures

  • Homogeneous Mixture - No visible layers, no settling out of particles (Very common in HS Chem)

  • Heterogeneous Mixture - Not Uniform throughout

    • Colloid - containing small particles that are small enough to be suspended

    • Suspension - Large dispersed particles that can settle out

Solution

  • A homogeneous mixture of 2 or more substances uniformly dispersed throughout a single phase

    • Solvent

      • The component that is in the highest quantity

    • Solute

      • The component that is in the lowest quantity

Solution = Solvent + Solute

Aqueous sol. (aq.) - homogeneous mixture w/ H2O as the solvent

Pure Substances

  • Elements

    • All atoms of the same element have the same atomic #

  • Molecules

    • A single particle of 2 atoms or more chemically bonded to each other

  • Compound

    • 2 or more diff. elements joined by chemical bonds

Diatomic Molecules of Elements

  • Same element bonded to each other

  • 7 elements like this

    • Nitrogen, hydrogen, oxygen, fluorine, Chlorine, bromine, iodine.

      • Mnemonic device

        • No Homework On Friday Clean Bedroom Instead