3The Periodic TablePeriodic means occurring or appearing at regular intervalsThe Periodic table is designed so that elements with similar characteristics occur or appear at regular intervals
4The Periodic Table The table can be divided in many ways Method 1 Metals (brown)Nonmetal (purple)Metalloids or Semi-metals (green)
5The Periodic Table Metals Most are solid at room temperature (except mercury, Hg)Usually are shiny solids when freshly cutGood conductors of heat and electricityMalleable (meaning can be flattened into a sheet)Ductile (meaning can be drawn into a wire)Most have high melting points and boiling points
6The Periodic Table Nonmetals Metalloids or Semi-metals 11 are gases, 5 are brittle solids, and 1 is a liquid at room temperaturePoor conductors of heat and electricityMost have low melting points and boiling pointsMetalloids or Semi-metalsThe seven elements that separate the metals and nonmetalsThe metalloids tend to have properties of both metals and nonmetalsEx: SiliconMetal-like in that it is a shiny solidNonmetal-like in that it is a brittle solidConductivity lies between that of a metal and non-metal
8The Periodic Table Groups Indicated by the number at the top of each columnAll elements within a group have similar characteristics or properties
9The Periodic Table Group 1 – Alkali metals Soft, shiny metals Low melting points compared to other metalsMost reactive of the metals that are not radioactiveWhen added to water they form a highly alkaline (basic) solution – hence the name alkali metals
10The Periodic Table Group 2 – Alkaline Earth Metals Shiny solids Less reactive than the Alkali metalsHigher melting points than the Alkali metals
11The Periodic Table Group 17 – Halogens All are gases except Bromine Colorful, corrosive nonmetalsMost reactive of all the nonmetalsThe group name halogen comes from the greek word hals, meaning salt, because the halogens are only found in nature in combination with other elements typically forming a salt.
12The Periodic Table Group 18 – Noble Gases Named noble because they lack reactivity.
13The Periodic Table Period Indicated by the number to the left of the row in which the element residesWe will discuss the importance to the period # in chapter 3.
14The Periodic Table Method 2 Main Group elements (yellow)Transition Metal elements (orange)Inner Transition Metal elements (blue)Are not given group #’s.To determine which period they are members of look at the elemental numbers (atomic #) given at the top of each box. (Expanded version on next slide)Elements are called the Lanthanide series because they follow element #57, LanthanumElements are called the Actinide series because they follow element #89, ActiniumThe divisions in method 2 will be discussed at length in Chapter 3