The Periodic Table Assignment Read Chapter 1 section

The Periodic Table

Assignment • Read – Chapter 1, section 6 – Chapter 3, section 4 – Chapter 3, section 5

The Periodic Table • Periodic means occurring or appearing at regular intervals • The Periodic table is designed so that elements with similar characteristics occur or appear at regular intervals

The Periodic Table • The table can be divided in many ways • Method 1 – Metals (brown) – Nonmetal (purple) – Metalloids or Semi-metals (green)

The Periodic Table • Metals – – – Most are solid at room temperature (except mercury, Hg) Usually are shiny solids when freshly cut Good conductors of heat and electricity Malleable (meaning can be flattened into a sheet) Ductile (meaning can be drawn into a wire) Most have high melting points and boiling points

The Periodic Table • Nonmetals – 11 are gases, 5 are brittle solids, and 1 is a liquid at room temperature – Poor conductors of heat and electricity – Most have low melting points and boiling points • Metalloids or Semi-metals – The seven elements that separate the metals and nonmetals – The metalloids tend to have properties of both metals and nonmetals • Ex: Silicon – Metal-like in that it is a shiny solid – Nonmetal-like in that it is a brittle solid – Conductivity lies between that of a metal and non-metal

The Periodic Table • Method 3 – Group – Period

The Periodic Table • Groups – Indicated by the number at the top of each column – All elements within a group have similar characteristics or properties

The Periodic Table • Group 1 – Alkali metals – Soft, shiny metals – Low melting points compared to other metals – Most reactive of the metals that are not radioactive – When added to water they form a highly alkaline (basic) solution – hence the name alkali metals

The Periodic Table • Group 2 – Alkaline Earth Metals – Shiny solids – Less reactive than the Alkali metals – Higher melting points than the Alkali metals

The Periodic Table • Group 17 – Halogens – – All are gases except Bromine Colorful, corrosive nonmetals Most reactive of all the nonmetals The 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.

The Periodic Table • Group 18 – Noble Gases – Named noble because they lack reactivity.

The Periodic Table • Period – Indicated by the number to the left of the row in which the element resides – We will discuss the importance to the period # in chapter 3.

The 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 58 -71 are called the Lanthanide series because they follow element #57, Lanthanum • Elements 90 -103 are called the Actinide series because they follow element #89, Actinium • The divisions in method 2 will be discussed at length in Chapter 3

The Periodic Table