Intro to Chemistry Notes 8th grade Physical Science

Matter- Something that has mass and volume The building blocks are atoms/elements Element: Pure substance that cannot broken down any more. Nucleus of atom composed of P+ and Neu. E- on the outside of nucleus Atoms: Basic particle from which all elements are made. Nucleus of atom composed of P+ and Neu. E- on the outside of the nucleus

More about matter… Protons: (+) charge particle in the nucleus of atom. (approx. ½ of mass of atom) Neurton: (0) charged particle in the nucleus of atom. (approx. ½ mass of most atoms) Electrons: (-) charged particles outside nucleus of atom (mini. mass)

States of Matter- Solid, Liquid, Gas, & Plasma Solid: Definite Shape & volume. Part. Arranged closely together Liquids: Definite Volume, no shape. Part. arrange closely and are free to move Gases: No definite shape or volume and move freely Plasma: High temps = electrons to be stripped of its electrons Conservation of Mass and Energy

Properties of Matter- Physical Properties: Ability to see changes in a substance without changing it into another substance. Chemical Properties: Ability to change a substance into another substance.

Physical Properties- Example: H20 (liquid, gas, solid), etc. Melt point, freezing point, color, density, solubility, conductivity, magnetism, malleability Do not react with other substances = mixtures. Mixtures: made of 2 or more elements or compounds = not chem. Combined Heterogeneous Mix: See diff. parts Homogeneous Mix: Cannot see diff. parts.

Chemical Properties- Change in physical properties Color change, gas release Ability to react with chemicals to form new chemicals Ex: Combustion, Electrolysis, Oxidation, Tarnishing

Chemical Bonding- Chemical Bond = attraction btw 2 atoms to molecules (2 or more atoms bonded = molecule) Compound = Molecule (change in physical props. Of in individual atoms)

Periodic Table- Mendeleev: Discovered patterns of props. Appeared when he arranged elements in order of Increasing atomic mass Prop of ele. Can be predicted from its location on periodic table http://www.corrosionsource.com/handbook/periodic/

More on the Periodic Table… Periods: Horizontal Rows: (Left to Right) Reactive Metal, less reactive metals, metalloids, nonmetals. Groups/Families: element that share similar characteristics. Elemental Squares Info: Atomic #, Chemical Symbol, Element Name, Atomic Mass. Concept Map Valence E- determine the Periodic Group