5.7 – NOTES Element Notes

I. Properties of s-Block Elements A. Representative elements (s and p blocks) - show wide range of properties B. Hydrogen - can behave like a metal (loses e-) or a nonmetal (gains e-) - most abundant element in the universe

C. Group 1A: alkali metals 1. Lithium – batteries, treats bipolar disorder 2. Sodium and potassium – most abundant alkai metals  essential to diet 3. Other alkali metals – very reactive

D. Group 2A: alkaline earth metals 1. Beryllium – non-sparking tools 2. Calcium – dairy; bones & teeth; chalk & limestone, contributes to hard water 3. Magnesium – fireworks and sparklets; chlorophyll, contributes to hard water 4. Strontium – fireworks (red-orange) 5. Barium – intestinal testing

II. Properties of p-Block Elements A. Group 3A: The Boron Group 1. Boron – Borax – most common form – boron fiber preceded carbon fiber 2. Aluminum – cans, foil, cars, bike frames (light weight) - Aluminum is the most abundant metal in earth’s crust (3rd overall in the crust) 3. Gallium – melts in hand, used for computer chips, 10x more efficient than silicon

B. Group 4A: The Carbon Group 1. Carbon – (organic chemistry) – forms more compounds than any other elements - 4 bonding sites, can make double or triple bonds 2. Silicon – 2nd most abundant element in Earth’s crust - SiO2 – quartz (sand)   3. Lead – Lead protects from radiation, can mimic calcium in the body 4. Tin – cars, bronze costume jewelry

C. Group 5A: The Nitrogen Group 1. Nitrogen – most abundant element in the earth’s atmosphere (79% N2) 2. Phosphorus – cealning products, fertilizers, ATP 3. Arsenic – poison 4. Antimony – Stainless Steel 5. Bismuth – Pepto bismol

D. Group 6A: The Oxygen Group 1. Oxygen – most abundant element in the earth’s crust (2nd most in atmosphere – 20% O2) 2. Sulfur – yellow solid (smells like rotten eggs) 3. Selenium – Solar panels, helps prevent cancer

E. Group 7A: The Halogens 1. Fluorine – toothpaste, most reactive elements 2. Chlorine – green poisonous gas, disinfectant 3. Bromine – only liquid nonmetal 4. Iodine – Purple Solid (sublimes)

F. Group 8A: Noble Gases 1. Helium – balloons and blimps, less dense than air 2. Neon – Neon Signs – glows a red orange 3. Argon – Most abundant noble gas (3rd in Earth’s atmosphere – 1%), double paned windows 4. Krypton – Double-paned windows

III. Properties of d-Block and f-Block Elements A. Transition metals 1. Formation of ions – lose e- 2. Magnetism and metals – permenant: Fe, Co, Ni - Temporary magnets: paramagnetic 3. Sources of transition metals – mined, some are pure, some are found as oxides (Fe2O3) 4. Uses of transition metals – infrastructure; jewelery, wiring

B. Inner transition metals – Rare Earth Elements 1. Lanthanide series - silvery metals, high melting points - usually found mixed together 2. Actinide series - radioactive properties - uranium – nuclear power - synthetic elements (#93 and up)