Atoms Atom- The smallest particle that can be called an element. All matter is made up of atoms. Made up of Protons(+), Neutrons, and Electrons (-)

Elements A pure substance All atoms of an element have the same # of protons. An element can not be broken into another substance No two elements are the same in their properties

Element Examples Element Hydrogen Oxygen Nitrogen Carbon Made up of Elements Water Air Rock

Concentrations The most abundant element in: The Universe Hydrogen (H) – 98% In the Earths Crust Oxygen- 47% Silicon- 28%

Three Atomic Particles Proton a. Found in the Nucleus b. Positively Charged (+) c. Is the Atomic #/whole # which = identity (C=6) 2. Electron a. Found in a cloud around the Nucleus b. Negative Charge (-) c. Same # as the Atomic Number (C = 6) d. Can be lost or gained to create charged particles (ions). e. Determine how elements will bond/react.

Neutrons a. Found in the Nucleus with the Protons. b. Neutral/No charge c. Creates Isotopes which are different versions of the same element (i.e.C14 vs. C12) d. Can be calculated by subtracting the atomic # from the atomic mass. Decimal # rounded - Whole # = # of neutrons (i.e. C = 12 – 6 = 6 neutrons)

Properties of Matter Physical Property- How a substance looks, feels, tastes, etc. Ex. Sugar is white, sweet and granular. Chemical Property- How a substance reacts to the world round it. Ex. Sugar will turn to a black solid when mixed with Sulfuric Acid.

How Matter Changes Conservation of Mass- Matter is neither created nor destroyed it just changes form. Physical Change- A change in form that does not result in a new substance. Ex. Sugar dissolves in water or any state change. Chemical Change- A change/reaction that creates a new substance. An indication this is happening is when you see a color change, heat, light, smoke/gas and a new byproduct. Ex. Oxidation (rust), Combustion (burning) or any Photosynthesis and Cellular Respiration.

Metals Physical Shininess Conduct Heat and Electricity Chemical High Density (Heavy) Ductile (Can be made into wire) Malleable (Can be flattened) All solids except Hg and H Chemical Tend to lose electrons to make positive ions. Tend to bond with non-metals like oxygen and water.(Corrosion)

Non Metals Physical Not Shiny Do not conduct electricity or heat Low Density (lighter) Brittle (not ductile or malleable) Can be gas, solid or liquid Chemical Tend to gain electrons to make negative ions Tend to bond with metals

Alkali Metals First Column Never found alone in nature because they are so reactive. React violently with water due to only having 1 valence electron

Halogens Second to last Column Never found alone in nature Highly reactive with Alkali Metals due to 7 electrons in the valence shell

Nobel Gases Last Column Do not react with anything due to having 8 valence electrons All gases

Valence Electrons Electrons in the outer most shell Can be determined by the column # (group) that the element exists in. All atoms trying to reach the magic 8 number of valence electrons. (Octet Rule) Number of valence electrons determines how reactive an element is and what type of bonds they form.

Ionic Bonding An ion is formed when an atom gives up an electron and becomes positive (+) or an atom gains an electron an becomes negative (–) An ionic bond is formed when two opposite charged atoms come in contact and stick to together. This the strongest of the chemical bonds

Covalent Bonding Bond created when two atoms share electrons Not as strong as ionic bonds (easier formed and easier broken) Carbon makes a lot of these

Electron Dot Model Determine the # of valence electrons Draw the atomic symbol Starting at “12 o’clock” place a dot at 12, 3, 6 and 9 If there are more than 4 valence electrons you then start pairing electrons at each spot. Bonding sites are all non-paired electrons