Transcript Slide 1
Metals, Nonmetals and Metalloids Where are Metals, Nonmetals, and Metalloids (Semimetals) located on the Periodic Table? Notice the difference between the appearance of the metal elements on the left and the nonmetal elements on the right. Click here for a better view of each of the elements. What are the Properties of Metals? What Are the Properties of Metals? • Metals are SOLIDS. (except for mercury, which is liquid at room temperature) • Metals are HARD. (except for the group 1 Alkali Metals: Lithium, Potassium, Sodium, Rubidium, and Cesium which are as soft as modeling clay) What Are the Properties of Metals? • Metals have shiny luster. (or metallic luster) LUSTER – the way an object’s surface reflects light What Are the Properties of Metals? • Metals are good conductors of heat. A copper frying pan A steel spoon in a mug of hot water For example, when a spoon touches a hot drink, the heat from the drink excites the electrons in the metal, and the electrons transfer the energy from one electron to another, carrying the heat all the way up the spoon quickly. What Are the Properties of Metals? • Metals are good conductors of electricity. Copper, silver, and gold are good electrical conductors. In a conductor, electric current can flow freely. Since metals have free electrons, they can carry a charge easily. Spool of silver wire Copper Wiring Gold plated HDMI cables What Are the Properties of Metals? • Metals are malleable. Malleable or Malleability - the ability to be shaped or formed by hammering or pressure; can be beaten into thin sheets Aluminum is malleable. What Are the Properties of Metals? • Metals are ductile. Ductility or ductile – can be drawn into a wire Spools of wire Copper Wiring Speaker wires Where do we find Metals on Earth? • Some metals like gold, silver, and platinum are found as pure substances in the earth’s crust because they are least reactive. • Most metals are reactive and are found as oxides (react with oxygen), carbonates (react with carbon), or sulfides (react with sulfur). Mineral: an element or compound which occurs naturally inside the earth’s crust Ore: a mineral from which metals can be extracted profitably Gold Mineral Iron Ore Let’s Review the Properties of Metals • Metals are usually – Solid – Hard – Shiny (luster) – Malleable – Ductile – Good conductors of heat – Good conductors of electricity What are the Properties of Nonmetals? What Are the Properties of Nonmetals? • Non metals may be solids, liquids or gases. What Are the Properties of Nonmetals? Solid Nonmetals Solids – Carbon, Sulfur, Phosphorus Gaseous Nonmetals Liquid Nonmetals Liquid – Bromine Gases – Fluorine Chlorine Nitrogen What Are the Properties of Nonmetals? • Nonmetals have a dull luster. They are not shiny! Example: Phosphorus What Are the Properties of Nonmetals? • Nonmetals are insulators. They do not conduct electricity or heat well. The atoms in nonmetals do not have loose electrons. Therefore, when electricity or something hot touches a non-metal, the energy does not move quickly through the material. What Are the Properties of Nonmetals? • Nonmetals are soft and brittle. Except for the diamond form of Carbon, which is a very hard solid! Sulfur White Phosphorus Iodine Carbon An interesting element: Carbon Have you ever broken the point of your pencil? That’s because it’s made of graphite, a substance made up completely of the brittle nonmetal Carbon. Diamonds are the hardest material of all, and they are made of the same element: Carbon. Look at how the carbon atoms are arranged in diamonds. Why do you think diamonds are harder than graphite? Carbon atoms in graphite What are the Properties of Metalloids? Which Elements are Metalloids? • Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium, Polonium, and Astatine are commonly classified as metalloids What are the properties of Metalloids? • Metalloids have physical properties of both metals and non-metals. – – – – Some are shiny Some are dull, They are somewhat malleable and ductile, They and can conduct heat and electricity at a lesser level than metals SILICON BORON ARSENIC What are the properties of Metalloids? • Some metalloids are useful semiconductors – Semiconductors are used in computer chips and other electronics – Semiconductors conduct just the right amount of electricity or heat