2.1+Composition+of+Matter

Matter - anything that has mass and takes up space. Mass - the amount of matter in something. Elements - pure substances that cannot be broken down into simpler substances. pure - all of the molecules are the same Periodic Table of the Elements - A chart of all known elements, in order of atomic number. Chemical Symbol - an abbreviation for the element. Chemical symbols will be 1, 2 or sometimes 3 letters that represent the element. The 1st Letter must be CAPITAL, the 2nd and 3rd letters (if present) must be lower case. Atom - the basic unit of matter. Nucleus - the central portion of the atom, contains protons and neutrons. Energy levels - "areas" surrounding the nucleus where electrons are found. 3 Subatomic particles The atomic number is the number of protons within an atom of that element, and is usually the number of electrons as well (except ions) The atomic mass, sometimes called the atomic weight, is the average of the number of neutrons + protons within an atom of that element. When finding the number of neutrons in an atom round the atomic mass to the nearest whole number and subtract the atomic number from it.
 * Subatomic Particle || Mass in Atomic Mass Units || Charge || Where found || How do you find the amount of them? ||
 * Electron || 0 AMU || Negative (-) || Energy Levels || Usually the atomic number (except ions) ||
 * Proton || 1 AMU || Positive (+) || Nucleus || ALWAYS the atomic number ||
 * Neutron || 1 AMU || Neutral or no charge || Nucleus || Atomic Mass - Atomic number ||

[|Venus Flytrap teaches the atom]

[|Periodic Table]

To Find the Number of Protons in an atom = Find its Atomic Number To Find the Number of Electrons in an atom (except ions) = Find its Atomic Number To Find the Number of Neutrons in an atom = Subtract the Atomic Number from the Atomic Mass (rounded to the nearest whole number)

[|Basic Chemistry]

To draw an atom:
 * Draw a circle in the middle, this is your nucleus. Inside the nucleus write the number of Protons and the number of Neutrons.
 * Around the nucleus Draw circles representing energy levels. The first energy level (closest to the nucleus) can hold 2 electrons, the second and all other energy levels can hold up to 8 electrons.

[|Drawing an atom] [|Better Drawing]

Ion - atom with an electrical charge. An ion either has a positive or a negative charge. A positive ion has lost one or more electrons, while a negative ion has gained one or more electrons. []

Isotope - atom with a different number of neutrons. Isotopes are why the atomic mass (atomic weight) is a decimal. The atomic mass (atomic weight) is an average of all of the isotopes. []

Compounds - molecules that are composed of two or more atoms that are chemically combined (bonded), the properties of the reactants are changed into new properties for the product. ex. Hydrogen gas (is flammable) + Oxygen gas (is flammable) = Water (not flammable) Reactants = Products

Bonding Covalent Bonds - Two or more atoms share electrons Ionic Bonds - One atom gains electron(s) while another loses electron(s), then opposite charges attract

[|SAT2 Chemistry]

[|Quizlet]