• METALS= LEFT SIDE OF PT • NONMETALS= RIGHT SIDE OF PT (except Hydrogen) • METALLOIDS= ALONG THE STAIRCASE (except Aluminum) 2 METALS & NONMETALS • Where are the metals and nonmetals on the PT? • What are the properties of metals and nonmetals? • What are metalloids? 3 Coloring in the Periodic Table Notice the difference between the appearance of the metals and nonmetals. Click here for a better view of each of the elements. Examples of Metal PROPERTIES OF METALS Physical Properties: Solid at room temperature - exception: Hg High density Silvery-gray - exception: Au and Cu Good Conductors Metallic luster (shine) Malleable Ductile 7 Physical Properties of Metals High Density – Heavy for their size Have Luster -shiny Are Conductors -heat and electricity move through them easily Malleable – Can be hammered into a different shape Ductile – Can be drawn into a wire Metals are solid, except for mercury Physical Properties of METALS LUSTER – the way an object’s surface reflects light Metals have shiny luster. (or metallic luster) When you leave a spoon in a cup of hot drink, the bit poking out of the drink gets hot. Why? Conduction! METALS are the best conductors of heat. This is because the electrons in metals move more freely than in non-metals, allowing the heat energy to travel across the metal. For example, when the spoon touches the 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. Best conductors: silver and copper Physical 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. Copper Wiring Physical Properties of METALS Metals are ductile. Ductility or ductile – can be drawn into a wire Chemical Properties of Metals Reactivity – the ease and speed with which an element combines, or reacts, with other substances. Metals usually react by losing electrons to other atoms (makes positive ion). Metals corrode easily Some metals are very reactive. Ex: Sodium (Na) reacts very strongly with water. 13 Chemical Properties of Metals Metals corrode easily. Corrosion – the deterioration of a metal due to a chemical reaction in the environment. Oxidation – reaction with oxygen molecules by losing at least one electron. Iron reacts slowly with oxygen in the air (oxidation), forming iron oxide, or rust. Reaction (Explosion) of Alkali Metals with Water https://www.youtube.com/watch?v=HvVUtpdK7xw Periodic Trends in Reactivity: the Alkali Metals https://www.youtube.com/watch?v=OR2Mg1UmIE0 14 Element Families • Just as human family members often have similar looks and traits, members of element families have similar chemical properties because they have the same number of electrons in their outer energy levels. • The electrons in the outer-most energy level are called valance electrons. 16 Element Families 17 Alkali Metals • The metals in Group 1 are called alkili metals. • These metals are the most reactive metals in the periodic table. • They are so reactive that they are never found as uncombined elements in nature. They have to be isolated in the lab. • The alkali metals form compounds that are similar to each other. • Alkali metals each have one outer energy level electron. • It is this electron that is removed when alkali metals react. • The easier it is to remove an electron, the more reactive the atom is. • The reactivity of alkali metals increase down the group. Alkali Metals Periodic Trends in Reactivity: the Alkali Metals https://www.youtube.com/watch?v=OR2Mg1UmIE0 Reaction (Explosion) of Alkali Metals with Water https://www.youtube.com/watch?v=HvVUtpdK7xw Why do atoms combine? Alkali Metals Valance electron Alkali Earth Metals • The elements of Group 2 are called the alkaline earth metals. • These metals are harder and denser, and melt at higher temperatures than alkali metals. • They are very reactive, though not as reactive as the alkali metals. • These metals are also never found uncombined in natures. Element Families 22 Transition Metals • The elements in Groups 3 through 12. • The transition metals include iron, copper, nickel, gold, and silver. • Most of these metals are hard and shiny solids. Ex. mercury. • With the exception of mercury, the transition metals often have high melting points and high densities. • They are also good conductors of heat and electric current, and are very malleable. • The transition metals are less reactive than the metals in Groups 1 and 2. Lanthanides and Actinides There are two rows of elements placed below the main part of the periodic table. The top row are the lanthanides. Compounds containing lanthanide neodymium (Nd) are used to make laser light, used for surgery, cutting metals. 24 Lanthanides and Actinides The elements below the lanthanides are called actinides. Many of these elements are not found in nature but are made artificially in laboratories. 25 Transuranium Elements Elements that follow uranium (U, 92) in the periodic table are transuranium elements. These elements are made, or synthesized, when nuclear particles are forced to crash into another. They are called synthetic elements. To make elements with atomic numbers above 95, scientists use devices called particles accelerator. 26 Element Families 27 Where do we find METALS? 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), sulfides (react with sulfur). Minerals : are elements or compounds which occur naturally inside the earth’s crust. Ore : is a mineral from which metals can be extracted profitably. THE NONMETALS 29 PROPERTIES OF NONMETALS Physical Properties: Can be gas, solid, or liquid at room temperature Come in all colors No metallic luster (dull) Poor conductors Brittle Odors or pungent Chemical Properties: Tend to gain electrons (makes negative ion) 30 The Periodic Table 31 Examples of NONMETALS Non metals may be solids, liquids or gases. Examples: Solids – Carbon, Sulfur, Phosphorus Liquid – Bromine Gases – Oxygen, Hydrogen, Nitrogen 33 Examples of NonMetals Physical Properties of NonMetals Dull – not shiny Poor conductors – means that heat and electricity do not move through easily Brittle – break easily Most nonmetals are gases at room temperature Physical Properties of NONMETALS Nonmetals have a dull luster. (They are not shiny!) Example: Phosphorus Physical Properties of NONMETALS Nonmetals are insulators. They do not conduct electricity or heat well. Physical 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 would you rather stir a hot pot with—a wooden spoon or a metal spoon? 39 An interesting element: Carbon Ever break the point of your pencil? That’s because it’s made of graphite, a substance made up completely of Carbon—a brittle nonmetal. However diamonds, the hardest material of all, 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 41 42 43 44 45 METALLOIDS 46 METALLOIDS Properties and characteristics of both metals and nonmetals Along the staircase/steps of the periodic table EXCEPT: Al, At 47 METALLOIDS Metalloids are the elements found along the stair-step line that distinguishes metals from non-metals. This line is drawn from between Boron and Aluminum to the border between Polonium and Astatine. The only exception to this is Aluminum, which is classified under "Other Metals". Metalloids have properties of both metals and non-metals. Some of the metalloids, such as silicon and germanium, are semi-conductors. This means that they can carry an electrical charge under special conditions. This property makes metalloids useful in computers and calculators The Metalloids are: Boron Silicon Germanium Arsenic Antimony Tellurium Polonium 48 METALLOIDS The elements contained in the classification of Metalloids: METALLOIDS Elements classified as Metalloids have physical properties of both metals and non-metals. All metalloids are solids at room temperature. Some are shiny, some are dull, they are somewhat malleable and ductile, and can conduct heat and electricity at a lesser level than metals. SILICON BORON ARSENIC METALLOIDS Some of the metalloids, such as silicon and germanium, are semi-conductors. Semiconductors are substances that can conduct electric current under special conditions. This property makes metalloids useful electronics (in calculators, radio, computers, telephones, etc.) They are useful because they conduct just the right amount of electricity or heat. PRACTICE! METAL, NONMETAL, METALLOID Hydrogen Magnesium Calcium Arsenic Carbon Helium Lead Aluminum NONMETAL METAL METALLOID 52 Lets Classify! ________ Silver ______ Iron ________ Oxygen ______ Calcium _________ Carbon ______ Sulfur _________ Aluminum _______ Sodium