Periodic TableGrouping Elements

Groups 1 & 2

-most reactive elements

-only have 1 or 2 electrons in outer level, so can easily give away electrons

-so reactive they are only found combined with other elements in nature

Group 1: Alkali Metals

-Outer level electrons - 1

-Reactivity - very reactive

-Other Shared Properties - soft, silvery, shiny, low density

-members - Lithium, Sodium, Potassium, Rubidium, Cesium, Francium

Group 2: Alkaline-earth Metals

-Outer level electrons - 2

-Reactivity - very reactive (less than alkali metals)

-Other shared properties - silver-colored,more dense than alkali metals

-Members - Beryllium, Magnesium, Calcium, Strontium, Barium, Radium

Groups 3 - 12: Transition Metals-Outer Level Electrons - 1 or 2-Reactivity - less than alkaline-earth metals-Other Shared Properties - shiny, conduct thermal energy & electric current well, higher densities & melting points (except mercury) than Groups 1 & 2EXAMPLES: Mercury, Gold, Iron, Titanium

Lanthanides and Actinides-transition metals from Period 6 & 7-placed at bottom of table to keep it from being too long-properties of elements in each row tend to be similar-also called rare-earth metals

Lanthanides-follow Lanthanum-shiny, reactive-used to make steel

Actinides-follow Actinium-all atoms are radioactive (unstable)-can change into atoms of other elements-every one after #92 (Uranium) is artificially created-Americium is used in small amounts in smoke detectors

Groups 13-16: Groups with Metalloids

-table shifts from metals to nonmetals

-each group contains at least one metalloid

-all but one contain at least one nonmetal

Group 13: Boron Group

-Outer Level Electrons - 3-Reactivity - Reactive-Other Shared Properties - solid @ room temperature-Members - Boron, Aluminum, Gallium, Indium, Thallium, Ununtrium

-Boron is a metalloid-Aluminum is the most common member (most abundant metal in Earth's crust)-used for lightweight automobile & aircraft parts, cans, foil, and wire

Group 14: Carbon Group-Outer Level Electrons - 4-Reactivity - Varies-Other Shared Properties - solid @ room temperature-Members - Carbon, Silicon, Germanium, Tin, Lead, Flerovium

-Carbon is a nonmetal that is essential to life on Earth-Silicon & Germanium are metalloids used in computer chips-Tin is useful because it is not very reactive

Group 15: Nitrogen Group-Outer Level Electrons - 5-Reactivity - Varies-Other Shared Properties - All but Nitrogen are solid @ room temperature-Members - Nitrogen, Phosphorus, Arsenic, Antimony, Bismuth, Ununpentium

-Nitrogen (gas @ room temperature) makesup 80% of the atmosphere-Nitrogen is fairly unreactive, but is combinedwith Hydrogen to make ammonia-Phosphorus is highly reactive & is not found alone in nature

Group 16: Oxygen Group (Chalcogens)-Outer Level Electrons - 6-Reactivity - Reactive-Other Shared Properties - All but Oxygen are solid @ room temperature-Members - Oxygen, Sulfur, Selenium, Tellurium, Polonium, Livermorium

-Oxygen makes up 20% of the atmosphere, is necessary for things to burn, and is needed by animals for life processes -Sulfur is used to make sulfuric acid (mostwidely used compound in chemical industry)

Groups 17 & 18: Nonmetals Only

-members of group 17 are the MOST reactive nonmetals

-members of group 18 are the LEAST reactive nonmetals

Group 17: Halogens-Outer Level Electrons: 7-Reactivity: very reactive-Other Shared Properties: Poor conductors of electric current, react violently with alkali metals to form salts, never found alone in nature-Members: Flourine, Chlorine, Bromine, Iodine, Astatine, Ununseptium

-only need to gain one electron to have a complete outer level-combine readily, especially with metals-physical properties differ greatly-Chlorine & Iodine are both used asdisinfectants, chlorine in watertreatment & iodine in hospitals

Group 18: Noble Gases-Outer Level Electrons: 8 (Helium has 2)-Reactivity: Unreactive-Other Shared Properties: colorless, odorlessgases @ room temperature-Members: Helium, Neon, Argon, Krypton, Xenon, Radon, Ununoctium

-unreactive because outer levels are complete-all found in atmosphere in small amounts-Argon is most abundant and is used to fill lightbulbs because it doesn't react with the metal filament-Helium is not very dense, so it is used to make blimps and weather balloons float-the Noble Gases are often used in "neon" signs because they produce colored light when introduced to an electrical current

Hydrogen Stands Alone

-Outer Level Electrons: 1-Reactivity: reactive-Other Properties: colorless, odorless gas @ room temperature, reacts explosively with Oxygen

-its properties don't match those of any group-it is placed above the Alkali metals becauseit only has 1 outer level electron-its physical properties are like those of nonmetals-it is the most abundant element in the universe-used in fuels (rocket fuel, hydrogen cars)