ATOMS AND MOLECULES

All matter, as we know it, is composed of atoms. 1. Atoms are the smallest unit of an element that still maintains the chemical properties of that element. 2. They are composed of:  Protons (p+) found in the nucleus Neutrons (n0) found in the nucleus Electrons (e-) found in orbitals around the nucleus

Atomic Structure...

3. Atoms obey the Kinetic Molecular Theory (KMT). See pp. 66 and 443 4. Atoms make up molecules which are 2 or more atoms chemically bonded together. Eg. H2O, CH3CH2OH

2. There are three (3) different types of molecules: Diatomics Made of one type of atom chemically bonded together in pairs The gang of NOF 7!! Eg. N2 O2 F2 Cl2 Br2 I2 H2

2. Polyatomics Made of many types of atoms bonded in groups of 2 or more that carry 1 overall charge. eg. H3PO4 NO3 CrO4 CN

3. Compounds A pure Substance made of 2 or more types of atoms. They are bonded together in simple whole number ratios. (Contain only 1 type of molecule). eg.: H2O CO2 NaCl HNO3 C6H12O6

Compounds obey the Law of Definite Composition… “Molecules of the same compound always have the same number and types of atoms bonded in exactly the same way.” (Every molecule of a compound is exactly the same.)

Why do compounds form?? Why do atoms bond with other atoms?? To Become stable like a Noble Gas!! All elements that bond obey the OCTET RULE… “Atoms tend to gain, lose or share electrons in order to acquire a full set of valence electrons” ( usually 8!)

TYPES OF ELEMENTS AND COMPOUNDS Compounds are of two types: Ionic Compounds Covalent Compounds  

Reactivity and Electron Configuration

The type of compound is determined by the kinds of elements that are chemically bonded to form the compound. Ionic – Metal + Nonmetal Covalent – Nonmetal + Nonmetal

The Periodic Table allows us to predict an element‘s properties based upon its position on the table. Metals Left and central part of the table up to the “line”. Non-Metals Right side of the periodic table (right of the “line”). Noble (Inert) Gases Far right side (Family 18) and don’t react with other elements.

The Elements Organized!

MOST METALLIC Increasing Metallic character LEAST METALLIC

4. Properties of metals versus non-metals: - Have a metallic shine/ luster - Usually have a dull appearance/ lack luster - Usually solid at room temperature - Usually gases at room temperature - Are malleable (don’t shatter) - Are brittle solids (i.e. are not malleable) - Are ductile (can be formed into sheets or wires) - Are not ductile - Are good conductors of electricity Do not conduct electricity

1)Do Hebden Pg. 66 Self-Test (every 2nd one) 2) Hebden Pg 1)Do Hebden Pg.66 Self-Test (every 2nd one) 2) Hebden Pg.68 exercise #1 3) Read over pg 161-164, and do # 31-39