Characteristics of Elements Unit 3.4

The 3 Types of Elements: Metals, Nonmetals, and Metalloids

Metals I. Metals- good conductors of heat & electricity Most elements are metals All but one (Mercury, Hg) are solid at room temperature. Lustrous- reflect light (shiny) Malleable- formed into shapes Ductile- drawn into wires

Groups of Metals Group 1: Alkali Metals: 1 Valence Electron Group 2: Alkali-Earth Metals: 2 Valence Electrons Groups 3-12 or 1B-8B: Transition Metals often form colored compounds, # of Valence Electrons change or transition (it gets very complicated ) Copper (Cu) Copper Sulfate (CuSO4)

Nonmetals II. Nonmetals- gases or brittle (easily broken) solids at room temperature. not malleable or ductile. do not conduct heat or electricity well not shiny Some are Diatomic- an element that consists of two atoms bonded together in nature Examples: (label these on your periodic table) H2 N2 O2 F2 Cl2 Br2 I2

Groups of Nonmetals Group 7: Halogens: 7 valence electrons These are all diatomic molecules and are very colorful Fluorine gas Chlorine gas Bromine gas Iodine Gas

Groups of Nonmetals Group 8: Noble gases: 8 valence electrons (except Helium, it only has 2) Don’t make compounds naturally because their valence electron level is full (we’ll talk more about this next unit)

Metalloid Metalloid-properties of both metals and nonmetals Metalloids are also called Semiconductors- element that conducts electric current under certain conditions

Allotropes Allotrope- same element with different forms and properties Examples: Diamond and Graphite: both made of Carbon Diamond (C) Each carbon atom bonded to 4 others Form an interconnected network. Strongest mineral Clear Graphite (C) Each carbon atom bonded 3 others Form layers that slide past each other “Lead” in pencils Soft mineral Gray

Which of these atomic structures is diamond?