Families of Elements Metals Nonmetals Semiconductors Alkali metals Alkaline-earth metals Transition metals Halogens Noble gases 3.3

Periodic Properties: Metals, Nonmetals and Metalloids Metals tend to give up electrons easily. They are on the left of the periodic table Nonmetals tend to gain electrons. They are on the right side. Metalloids (semi-conductors, metalloids) are on the border of the zigzag line between metals and nonmetals.

Metals & Nonmetals

Metals Nonmetals

Properties of Metals Good conductors of heat and electricity; Most are shiny Most are solid Malleable – shapes easily Ductile – stretch into wire Four different kinds of metals

Alkali Metals Group # 1 elements All are soft and shiny All react violently with water Atoms are very reactive because they have only one valence electron that is easily removed to form a cation Not found in nature as elements, only within compounds

Examples/Uses of Alkali Metals

Alkaline-Earth Metals Group # 2 elements Less reactive than Group # 1 Have two valence electrons, that are easily lost React to form positive cations

Examples/Uses of Alkaline-Earth Beryllium Magnesium Calcium Strontium Barium Radium

Transition Metals Located in the (the “B”) elements Much less reactive than other metals All are conductors electricity and heat Have varying number of valence electrons, means….. Some have more than one possible charge All elements with atomic numbers greater than 92 are man-made (the transuranic elements)

Examples/Uses of a few Transition Metals Gold Silver Mercury Tungsten Nickel Manganese Uranium Many more….

Nonmetals Except for Hydrogen, all nonmetals are on the right Nonmetals and their compounds are plentiful on earth

Examples/Uses of Nonmetals Carbon Oxygen Nitrogen Sulfur Phosphorous Selenium

Halogens Group # 17 elements Have 7 valence electrons Are highly reactive

Examples/Uses of Halogens

Noble Gases On the extreme right side of the periodic table Elements are very UNreactive Have FULL valence energy level (He with 2 all others with 8 valence electrons) Do not form ions

Examples/Uses of Noble Gases

Semiconductors Along the borderline between metals and non-metals Sometimes called “metalloids” or “semi-metals” Some characteristics of both metals and nonmetals Only 6 elements

Examples/Uses of Semiconductors

Radioactivity All elements with atomic numbers of 84 – 112 are radioactive Also – elements # 43 Technetium and # 61 Promethium