Most Important tool in chemistry. Used to understand and predict the properties of elements “periodic” – repeated in a pattern Go to slide 2

Periodic Law – when elements are arranged by increasing atomic number, there is a periodic repetition of their chemical and physical properties. Go to slide 3

Dmitri Mendeleev Go to slide 4 Russian chemist Proposed the first periodic table in 1871 Arranged by increasing atomic mass Go to slide 4

Henry Moseley British physicist Developed an arrangement similar to that of the modern periodic table in 1914 Arranged by increasing atomic number Cleared up the inconsistencies of Mendeleev’s periodic table Go to slide 5

Solid – state of matter with its own definite shape and volume Go to slide 6

Liquid – state of matter that flows and has constant volume Go to slide 7

gas – state of matter that flows to conform to the shape of its container, and fills the entire volume of its container Go to slide 8

Metals: Lustrous (shiny) Malleable (pound into sheets) Ductile (drawn into wires) Good conductors (of electricity and heat) On the left side of the stair-step on the periodic table Go to slide 9

Non-metals: Not lustrous (dull) Poor conductors (of electricity and heat) Physical properties (of most non-metals): Brittle Powdery Solids or gases On the right side of the stair-step on the periodic table Go to slide 10

Metalloids (a/k/a semimetals) Have properties of both metals and non-metals Along the stair-step line on the periodic table Go to slide 11

Groups (a/k/a Families) Columns Elements in each group have similar properties Groups 1, 2, 13, 14, 15, 16, 17, and 18 are called “Main Groups” or “Representative Groups” Elements in each main group have the same number of valence electrons Valence electrons determine the chemical properties of the element Go to slide 12

Periods Rows Rows end when energy levels are filled Go to slide 13

Energy levels Electrons in the electron cloud of an atom have different amounts of energy. Electrons in levels close to the nucleus have less energy than electrons in energy levels farther away from the nucleus. Go to slide 14

Group 1 – Alkali Metals Elements contain 1 valence electron in the outer energy level Most reactive elements Oxidation number is 1+ Softer than other metals Do not occur naturally in elemental form Go to slide 15

Group 2 – Alkaline Earth Metals Elements contain 2 valence electrons in outer energy level Very reactive Oxidation number is 2+ Go to slide 16

Group 13 – Boron Group Main group name is 3A Elements have 3 valence electrons in outer energy level Oxidation number is 3+ Go to slide 17

Group 14 – Carbon Group Main group name is 4A Elements have 4 valence electrons in outer energy level Contains non-metals, metalloids, and metals Oxidation number can be 4+ or 4- Go to slide 18

Group 15 – Nitrogen Group Main group name is 5A Elements have 5 valence electrons in outer energy level Oxidation number is 3- Go to slide 19

Group 16 – Oxygen Family Main group name is 6A Elements have 6 valence electrons in outer energy level Oxidation number is 2- Go to slide 20

Group 17 – Halogens Main group name is 7A Elements have 7 valence electrons in outer energy level Oxidation number is 1- Very reactive Readily react with Group 1 metals Go to slide 21

Group 18 – Noble Gases Main group name is 8A Complete outer energy level Helium has 2 valence electrons All other noble gases have 8 valence electrons “I eight, I full” Oxidation number is 0 Go to slide 22

Transition Metals – Groups 3-12 Ductile, malleable, good conductors Valence electrons vary Group 11 is called the “coinage metals” Copper (Cu) Silver (Ag) Gold (Au) Go to slide 23

Inner Transition Metals: Fit within transition metals between groups 3 and 4, in periods 6 and 7 Lanthanides (atomic numbers 58-71) Actinides (atomic numbers 90-103) Actinides are radioactive and unstable Rare Do not exist in nature Difficult to research