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

1. Hydrogen

2. Oxygen

3. Nitrogen

4. Carbon

Made up of Elements

1. Water

2. Air

3. Rock

Concentrations

The most abundant element in:

The Universe

Hydrogen (H) – 98%

In the Earths Crust

Oxygen- 47%

Silicon- 28%

Three Atomic Particles1. Proton

a. Found in the Nucleusb. Positively Charged (+)c. Is the Atomic #/whole # which = identity (C=6)

2. Electrona. Found in a cloud around the Nucleusb. 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.

3. Neutronsa. 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

1. Physical Property- How a substance looks, feels, tastes, etc.

Ex. Sugar is white, sweet and granular.

2. 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 ChangesConservation of Mass- Matter is neither created

nor destroyed it just changes form.

1. Physical Change- A change in form that does not result in a new substance.

Ex. Sugar dissolves in water or any state change.

2. 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

Physical1.Shininess2.Conduct Heat and Electricity3.High Density (Heavy)4.Ductile (Can be made into wire)5.Malleable (Can be flattened)6.All solids except Hg and H

Chemical1.Tend to lose electrons to make positive ions.2.Tend to bond with non-metals like oxygen and water.(Corrosion)

Non MetalsPhysical1.Not Shiny2.Do not conduct electricity or heat3.Low Density (lighter)4.Brittle (not ductile or malleable)5.Can be gas, solid or liquid

Chemical1.Tend to gain electrons to make negative ions 2.Tend to bond with metals

Alkali Metals

1. First Column2. Never found alone in

nature because they are so reactive.

3. React violently with water due to only having 1 valence electron

Halogens

1. Second to last Column2. Never found alone in nature3. Highly reactive with Alkali Metals due to 7

electrons in the valence shell

Nobel Gases

1. Last Column2. Do not react with anything due to having 8

valence electrons3. 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 Model1. Determine the # of valence

electrons

2. Draw the atomic symbol

3. Starting at “12 o’clock” place a dot at 12, 3, 6 and 9

4. If there are more than 4 valence electrons you then start pairing electrons at each spot.

5. Bonding sites are all non-paired electrons