Elements and Their Properties Test on Friday March 15

Metals Gold was the first metal used (6000 years ago) followed by copper and silver. Found on the periodic table to the left of the stair step.

Properties of Metals Good conductors of heat and electricity All but one (Mercury) is a solid at room temperature Reflect light (luster) Can be hammered into sheets (malleable) Can be stretched into wires (ductile)

Bonding in Metals The atoms of metals give up electrons to the atoms of nonmetals in ionic bonding. Occurs when a metal bonds to a nonmetal. Positively charged metallic ions are surrounded by a cloud of electrons in metallic bonding. The electrons in metallic bonding move freely between the atoms. Occurs when a metal bonds to another metal.

Alkali Metals Group 1 on Periodic Table Have one electron in their outer energy level Have properties of all metals Softer than other metals Most reactive They are so reactive they don’t exist by themselves in nature, only bonded to something else. Li is used to treat bipolar disorder Used in batteries

Alkaline Earth Metals Group 2 on the Periodic Table Each AEM has two electrons in its outer energy level. Very reactive Mg is used in fireworks Ca is a vitamin needed to stay healthy and develop strong bones Ra is radioactive and used to treat cancers

Transition Elements Groups 3 – 12 on the periodic table Most familiar Not very reactive Can be found in nature Iron, Cobalt, Nickel used to make steel and other alloys (mixture of metals) Gold, silver and copper are known as the coinage metals because they are used to make coins.

Inner Transition Metals The bottom two rows on the periodic table Lanthanides Elements 58 – 71 Combine to produce the colors on tv screens Actinides Elements 90 – 103 Radioactive and Unstable Used in photography, nuclear reactors, and weapons

Metals in the Crust Metals are found in the earth’s crust and must be mined and processed. They are originally ores (combined with other elements) They are refined to separate the metal from the rock This normally involves heating until the metal melts. This process can be very expensive

Metals Quiz What does it mean to be malleable? What does it mean to be ductile? What is luster? Where are the metals located on the periodic table? What happens to the reactions of metals with water as you move down the periodic table?

Nonmetals Usually gases or brittle solids at room temperature Not malleable or ductile Do not conduct electricity or heat Not shiny Located on the right hand side of the stair step (except for Hydrogen)

Nonmetal Bonding Nonmetals bonding can be ionic Or covalent One atom loses its outer electrons so another atom can take them Or covalent Atoms share the outer electrons

Hydrogen 90% of atoms in the universe are Hydrogen Most of the hydrogen on earth is found in water Hydrogen is a diatomic molecule Two identical atoms bond together You will never find H in nature, only H2 Very reactive because it only has one electron Normally that electron is lost to form H+

Halogens Group 17 Very reactive Have 7 electrons in the outer energy level Forms a salt when it reacts with a nonmetal Used in pools, bleaches, toothpaste, and cosmetics Iodine undergoes sublimation (changes from a solid to a gas without turning into a liquid)

Noble Gases Group 18 They have a full outer energy level They are stable and no natural compounds exist naturally Used in balloons and neon lights

Nonmetals Quiz What does it mean to be a diatomic molecule? How is H different from H+? How are solid nonmetals different from solid metals? What happens to the electrons in an ionic bond? What happens to the electrons in a covalent bond?

Metalloids Can form ionic and covalent bonds with metals and nonmetals Have metallic and nonmetallic properties Some can conduct electricity, but not very well Sometimes called semiconductors Located on the stair step on the periodic table (Al is on the stair step, but is NOT a metalloid, Al is a metal)

Boron Group Consists of Boron And Aluminum Used in laundry soap and antiseptic And Aluminum Most abundant metal in the earth’s crust Strong and light weight Used in construction of buildings, cars and airplanes

Carbon Group Consists of Carbon Silicon And Germanium Nonmetal Used as a semiconductor (element that conducts electricity only under certain conditions) for electronics Most silicon is found in sand, rocks, and dirt And Germanium Used as a semiconductors

Allotropes Allotropes are different forms of the same element. Carbon has 8 allotropes