Metals Metals are on the left side of the Periodic Table Metals have 1, 2, 3, or 4 electrons in their outermost energy level Most metals have only 1 or 2 electrons in the outermost energy level. These valence electrons are loosely (weakly) held the physical and chemical properties of metals. They behave rather like positive nuclei in a “sea” of loosely held electrons Physical Properties Luster (shiny)= light reflecting off the electrons. Very good conductors of heat and electricity The loosely held electrons are able to move an electric current (movement of electrons) Silver (Ag) is the best conductor: Copper (Cu) is the second best. Malleable and ductile the (+) nuclei can slip through the loosely held electrons High density and high melting points Chemical Properties Metals tend to lose their outermost electrons 8 electrons in the outer shell= a stable configuration. The more loosely held the electrons, the more easily they are lost, the more reactive the metal. Metals with 1 outer electron are the most weakly held the most reactive metals (Group 1A, 1). Those with 2 outer electrons (Group IIA, 2) are slightly less reactive e As you move down a group, the elements become more reactive because the outer electrons are further from the nucleus Chemical Properties Francium (Fr) is the most reactive metal. Metals tend to react with air and water Corrosion= a gradual chemical reaction which wears away a metal. Rust is the corrosion of iron. Tarnish is the corrosion of Silver (Ag) Nonmetals On the right side of the Periodic Table Nonmetals have 4, 5, 6, 7, or 8 electrons in the outermost energy level These valence electrons are tightly held the physical and chemical properties of nonmetals The positive nuclei are “locked” between the tightly held electrons which are unable to move The number of electrons in the outer shell determines the chemical and physical properties of an element Physical Properties Usually opposite to the physical properties of metals Dull Nonconductors or poor conductors of heat and electricity Brittle Generally lower densities and melting points Chemical Properties Nonmetals tend to gain electrons 8 electrons in the outer shell= a stable configuration Nonmetals that need 1 electron(s) Group VIIA, 17 Or 2 electrons (Group VIA, 16) to fill their outer energy level are the most reactive The Noble Gases are nonreactive= inert because the outer shell is full (complete) and thus stable Metalloids Solids between the metals and nonmetals They will conduct, but not as well as metals They are ductile and malleable, but not as much as metals because they have 3, 4, 5, 6, or 7 electrons in the outer shell Metalloids with 6 or 7 electrons in the outer shell are large atoms The outer shell is far from the nucleus and the atom isn’t as tightly held to the nucleus. Active Metals Group 1A (1) = the Alkali metals Lithium (Li), Sodium (Na), Potassium (k), Rubidium (Rb), Cesium (Cs), and Francium (Fr) Hydrogen is not an alkali metal it is actually a nonmetal This group easily loses its 1 outer electron so it is the most reactive group of metals It is never found in the free or uncombined state in nature It must be stored under oil to protect it from oxygen and water It reacts violently with oxygen and water Active Metals The Alkali metals form important compounds such as NaCl They are soft, silvery, and have lower melting and boiling points than other metals Sodium (Na) and Potassium (K) are the most important to plants and animals Active Metals Group IIA (2) = the Alkaline Earth metals Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), Radium (Ra) This is the second most reactive group of metals. They are also never found free in nature because their 2 outer electrons are easily lost They are harder, denser, and have higher melting and boiling points than Group 1 Calcium and Magnesium are the most important both in biology and industry Magnesium is used in fireworks, cars, planes, spacecraft, baseball/softball bats, and old fashioned flashbulbs Transition Metals Rows 3-12 (in middle of periodic table) Often occur as uncombined elements Often form colored compounds Paints—cadmium=yellow, cobalt=blue Toxic– limited use Iron triad– Iron, cobalt, nickel Used to create steel Iron most widely used of all metals Nickel used to give added strength and shiny, protective coating Transition Metals Coinage metals– copper, silver, gold Most coins now made of nickel and copper Copper used in electrical wiring Zinc, cadmium, mercury Zinc and cadmium used to coat other metals Cadmium used in rechargeable batteries Mercury– only metal that is liquid at room temperature Used in thermometers (not much now), thermostats, switches, and batteries poisonous Lanthanides Elements from 57-71 Commonly referred to as the rare earth metals (along with scandium and yttrium) Most are not that rare though Many more common than gold Uses: catalysts Deflect UV and Infrared rays so are often used in the production of sunglasses lasers Actinides Actinides– 89-103 Thorium and Uranium only ones occur in substantial amounts in nature Small amounts of plutonium have been found The rest are synthetic Nuclear weapons have released six others into nature Bomb on Nagasaki had a plutonium charge Halogens Group 17 (VIIA) Very reactive Found only in nature in compounds or ions Exists as diatomic molecules Only periodic group exhibiting all 3 states of matter at room temp. If gains an electron from a metal it forms a salt Fluorine is most reactive Added to toothpaste and water to stop Chlorine disinfects water (most abundant) Bromine is only nonmetal liquid at room temp. Noble Gases Stable Eight electrons in outer shell (except He) All are odorless and colorless He used to ease breathing for asthma patients Xenon is used as an anesthetic