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2.2 Using the Periodic Table Elements can be divided into three broad classes based on their general properties: metals, nonmetals and metalloids. Most elements are metals. Metals Are good conductors of electricity Are able to reflect light when cleaned or cut All metals, except mercury, are solid at room temperature. Most metals are ductile and malleable Nonmetals are elements that tend to have properties that are the opposite of metals. Most non metals are gasses at room temperature Sulfur & Phosphorous are solids at room temperature Bromine is a brown liquid. Nonmetals are generally poor conductors of electricity and heat. Solid nonmetals are brittle Metalloids are elements that have properties that are similar to both metals and nonmetals. The behavior of metalloids is dependent on the conditions that they are exposed to. The boiling points, melting points, and densities of the metalloids vary widely. , possesses a metallic luster, yet it is an inefficient conductor and is brittle. The reactivity of the metalloids depends on the element with which they are reacting. For example, acts as a nonmetal when reacting with sodium yet as a metal when reacting with fluorine. The intermediate (in between) conductivity of metalloids means they tend to make good semiconductors. Most elements are __________. List 3 properties of each, metals, non-metals and metalloids. Give three examples of each, metals, non-metals and metalloids.(Not in the presentation) If they are generally poor conductors, they are members of which group? Are all metals solids at room temperature? Explain. Identify the properties of each of the following: Niobium(Nb), Palladium(Pd), Krypton(Kr), Fluorine(F), Silicon(Si) The color of the element symbol gives information on the physical state of the element at room temperature. Black = solid @ room temp Red = Liquid@ room temp Blue = Gas @ room temp Elements printed in black, red or blue are found in nature. Those printed in 0utline are not found in nature Squares in the Periodic Table Background colors are used to distinguish groups of elements. We now know that there are 3 major classes of elements: __________, __________, ____________. We also know that there are 8 groups of elements: __________, _________, ___________, __________, __________, _________, ___________, ___________. We know that the color of the element symbols can communicate something to us, like; We know that the background colors can also tell us something, like; Work in pairs around your table.(2 people) Have one person get a computer While the other gets 2 copies of the handout with instructions. Read through all of the instructions before beginning the activity. Collect all of the data and record it on your sheet. You will be given 2 class periods to complete the activity, but it will take that long so do not waste time! Trends in Atomic Size Group Trends in Atomic Size As one moves down a group the size of the atom’s atomic radius increases. Periodic Trends in Atomic Size Atomic size decreases across a period from left to right. Ions An ion is an atom or group of atoms that have a positive or a negative charge. Ions form when electrons are transferred between atoms. An ion with a positive charge is called a cation. Metallic elements form cations by loosing one or more electrons An ion with a negative charge is called an anion. Nonmetallic elements form anions by gaining one or more electrons Trends in Ionization Energy Ionization energy is the energy required to remove an electron from an atom in its gaseous state. First ionization energy tends to decrease from top to bottom in a group and increase from left to right across a period. The energy required to remove the first electron is called the first ionization energy. Trends in Ionic Size Cations ( pos. change) are always smaller than the atoms from which they form. Anions ( neg. charge) are always larger than the atoms from which they form. This change in atomic size is due to the change in the force of attraction between the protons and between the electrons. Spread out Trends in Electronegativity Electronegativity is the ability of an atom of an element to attract electrons when an element is in a compound. In general, Electronegativity values decrease from top to bottom within a group. For representative elements ( s- and p- block elements), the values tend to increase from left o right across a period. Electron Configurations in Groups Elements can be sorted into noble gases, representative elements, transition metals, or inner transition metals based on their electron configurations. Electron Configurations in Groups The Noble Gasses (Group 8 A) The noble gasses are non metals whose s and p sublevels of the highest occupied energy level are filled These gasses are also called the inert gasses because they rarely take part in chemical reactions. Electron Configuration in Groups The representative elements occupy groups 1A through 7A in the periodic table. The representative elements display a wide range of physical and chemical properties. The s and p sublevels of the highest occupied energy level are not filled. The group number equals the number of electrons in the highest occupied energy level Electron Configuration in Groups The transition elements in the B groups separate the A groups. The transition metals are one of the B Group elements in which the highest occupied s sublevel and a nearby d sublevel generally contain elections The inner transition metals are B Group element which have f orbitals that are occupied by electrons. These elements are sometimes called the rareearth elements