10 Chem Chapter 6 Groups Of Elements

Groups of Elements Reactive Metals: The s-block Alkali Metals Properties -

Shiny solids that are malleable, ductile, and good conductors of electricity Have low densities and melting points Have intense chemical reactivity, tarnish rapidly Are most reactive because of their low ionization energy

Sources and Uses -

Since alkali metals are very reactive, they are never found as free, or uncombined, elements in nature Usually found in compounds and distributed widely across the world Compounds are very soluble in water Sodium is used commercially in large amounts

Alkaline Earth Metals Properties -

Have higher densities and melting points when compared to Alkali metals Higher ionization energies and aren’t as reactive but heavier metals can react with water

Sources and Uses -

They are not found in nature in an elemental state The metals are sometimes added together and make up alloys

Transition Metals: The d-block elements -

Transition metals play an important role in living organisms and are extremely valuable as strong, structurally useful materials Properties - Have high densities and melting points - Transition metals vary family to family Inner Transition Metals: The f-block elements - Divided between Lanthanides and Actinides - Electron configuration doesn’t follow a pattern The Lanthanides - Soft, silvery metals - Somewhat less reactive than the heavier alkaline earth metals - Too reactive to be used as structural materials - They tarnish readily in air and react slowly in water - Widely distributed in nature

The Actinides - All isotopes of these elements are radioactive - Only thorium and uranium occur to any extent in nature Nonmetals: The p-block elements The Boron Group (Group 3A) - All elements form 3+ ions by loss of these valence electrons - The most important element in aluminum: it has low density but when alloyed with other metals, it is quite strong The Carbon Group (Group 4A) - Carbon is a major component of fossil fuels - It is a common air pollutant - Other important elements are silicon, germanium, tin, and lead The Nitrogen Group (Group 5A) - Nitrogen: makes up approx 80 % of Earth’s atmosphere - Nitrogen is colorless, odorless gas composed of N2 molecules - Phosphorus is another abundant crystal element found combined with oxygen and other elements in minerals The Oxygen Group (Group 6A) - Oxygen is the most abundant element on Earth - Elemental oxygen is colorless, odorless, and tasteless - Oxygen is required for respiration - Sulfur is a gas with an unpleasant odor: Large productions of sulfur are used in paints, plastics, insecticides, etc. The Halogens (Group 7A) - Consists of nonmentals: Flourine (F), Chlorine (Cl), Bromine (Br), Iodine (I), and Astatine (At). - Halogens react with most metals and with nonmetals - They are highly reactive and don’t occur as free elements in nature The Noble Gases (Group 8A) - Noble gases lack reactivity and have a tendency to remain apart - Most abundant noble gas is argon - Helium is commercially the most important Hydrogen: One of A Kind - Hydrogen is a nonmetal that exists as a gas - It’s colorless, odorless, and composed of H2 molecules - It’s rare in the atmosphere because it is light enough to escape Earth’s gravitational attraction - It is the most abundant element on Earth