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Physical Science Chapter 19. Elements and Their Properties. 1. How to Count Atoms. The symbol of an element represents one atom of that element. Ex. Ba =1 atom of barium
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Physical Science Chapter 19 Elements and Their Properties 1
How to Count Atoms • The symbol of an element represents one atom of that element. Ex. Ba =1 atom of barium • A subscript is a number written at the lower right corner behind the symbol of an element. If there is more than one atom of the element, then a subscript is used to indicate the number of atoms. Ex. Cl2 – 2 atoms of chlorine • A subscript outside a parenthesis multiples all the elements inside the parenthesis. Ex. Ca3(PO4)2 = 3 calcium, 2 Phosphorus, and 8 oxygen atoms.
How to Count Atoms • A coefficient is a number written in front of a chemical symbol and indicates the number of atoms of that element or number of molecules. Ex. 3C =3 carbon atoms 2NaSO4 = 2 sodium, 2 sulfur and 8 oxygen atoms • A subscript is a number wirtten after an atom in a formula and indicates the number of atoms of that kind in the molecule. Ex. H2SO4 The subscript of H =2 and subscript of O = 4. • Note: A coefficient multiples the number of atoms of each element in the formula. More Practice Now
19:1 • Metals conduct heat and electricity, reflect light (luster); are malleable -__________________-- are ductile -_________________-- ionic bonding --combine with nonmetals by losing electrons-, Can be hammered or rolled into sheets Can be drawn into wires Video 1.a Metals 6.31 2
19:1 Quick Notes • Metallic bonding (positively charged metallic ions are surrounded by a cloud of electrons; ions are in sliding layers and electrons are weakly held; readily form ionic bonds with nonmetals. 3
19:1 Quick Notes B. Alkali Metals are softer and more reactive than other metals; highly reactive with ________ & _________; combine readily with other elements due to _______ electron in outer energy level; they have multiple use: oxygen water single 6
19:1 Quick Notes sodium, potassium, and lithium compounds • Human health– • Photocells– • Francium- rubidium or cesium A radioactive element which breaks down giving off particles and energy 7
C. The Alkaline Earth Metals not are _____ found naturally in elemental form: ______ electrons in outer energy level. two Alkaline Earth Metals 6
19:1 Quick Notes Stontium and magnesium found in fireworks; magnesium in vehicles, ladders, and bats; calcium in statues and countertops. a. Applications— 10
19:1 Quick Notes Calcium in bones; barium in disease diagnoses; radium formerly used in cancer treatment. b. Human body— 11
19:1 Quick Notes • Transition Elements—often occur in nature as combined elements • Typically form coloredcompounds—chromium is found in rubies and emeralds; 12
19:1 Quick Notes Iron, cobalt, and nickel Iron • Iron triad-- _______, ____, ____. i. _________-- most widely used of all metals and main ingredient in steel; abundant in Earth’s crust. • _______ and nickel – used in some steel • _____ used to coat other metals. Cobalt Nickel
19:1 Quick Notes coinage • Copper, silver, gold --__________ metals since once were commonly used in coins. i. ______________ used in electrical wiring because it is a superior electricity conductor. Copper 15
19:1 Quick Notes Silver • ___________ used in photographic film and paper, jewelry. • _____________ used in jewelry. Gold 16
19:1 Quick Notes 12 • Zinc, cadmium, mercury—Group ____ on the periodic table. i. Zinc and cadmium are often used to coat or plate other metals. ii. ________ only room temperature liquid metal; used in thermometers and batteries. Mercury 18
19:1 Quick Notes E. Inner Transition Metals—seem disconnected from the rest of the periodic table. a. The Lanthanides—include _______, cerium, praseodymium, samarium, europium, gadolinium, and terbium. lanthanum 20
19:1 Quick Notes Actinides unstable b. The _________________--all are radioactive and __________, ____________ is the best known. uranium 7 Lanthanide and Actinide Series .47 21
19:2 Quick Notes brittle A. Properties of nonmetals—usually gases or ______ solids at room temperature; are not ________ or ____________; usually poor _____________ of heat and electricity; usually not lustrous. malleable ductile conductors
19:2 Quick Notes electrons • Ionic compounds—form when nonmetals gain _______ from metals and become ____________ ions. • Covalent compounds-form when nonmetals share electrons with other ________________. negative nonmetals 24
19:2 Quick Notes Hydrogen • __________-- most common element in the universe. About 90% of all atoms in the universe are Hydrogen. a. A _________ ______-- two atoms of the same element in covalent bond. Diatomic molecule
19:2 Quick Notes • Highly reactive element found mostly on Earth as part of water. • Halogens --include bromine, iodine, fluorine, chlorine, and astatine. How Chlorine Bonds 10 Nobel Gases 1.15 9 Halogens .44 26
19:2 Quick Notes salt 1. A _________ forms when a halogen gains one electron from a metal. 27
19:2 Quick Notes Chlorine 2. Uses of halogens i. ___________- disinfectant and bleach ii. __________ dyes in cosmetics iii. ________ hormone regulation. Bromine Iodine 28
19:2 Quick Notes Sublimation c. ___________ a solid changes directly into a gas without first becoming a liquid. 30
19:2 Quick Notes • Noble Gases—exist as isolated, stable atoms. a. ________--used in blimps and balloons. b. ______, argon, and krypton—used in lights. helium Neon
19:3 Quick Notes Metalloids A. Properties of ___________-- form ionic and covalent bonds; have some metallic and some nonmetallic properties; partial conduction gives them ______________ characteristics. semiconductor 33
19:3 Quick Notes Boron • The ____________ Group—named for the first element in Group 13. a. ___________ used in water softening products, antiseptics and fuels. Boron 34
19:3 Quick Notes Aluminum b. _____________ --abundant in Earth’s crust; used in cans, foil wraps, pans, building materials, and aircraft. 35
19:3 Quick Notes carbon 4 • The ____________ Group-- ___ electrons in outer energy level. a. _____________ found in coal, oil, natural gas, and foods carbon 13CarbonSiliconGermaniumTinLead 1.44 -- 37
19:3 Quick Notes allotrope • Silicon occurs as an ________- same element with different molecular structures. i. ___________ found in sand, rocks and soil. silicon 38
19:3 Quick Notes semiconductors • The main component in ___________ which conduct electricity under certain conditions. c. _____________ is also used in semiconductors. Germanium 39
19:3 Quick Notes Tin • ______________-- used to coat other metals. • Diamonds, graphite and buckminsterfullerene are all _________________ of carbon. allotropes 40
Group 14 Carbon Group
19:3 Quick Notes Nitrogen 15 • The __________ Group-- ____ electrons in outer energy level; tend to form covalent bonds. a. _________ used to make nitrates and ammonia. Nitrogen 14NitrogenGroup 1.22
19:3 Quick Notes Phosphorus • _____________ - used in water softeners, fertilizers, match heads, fine china. • __________ and ___________ used with other metals to lower their melting points. bismuth Antimony 43
Group 15 Nitrogen Group
19:3 Quick Notes Oxygen • The ___________ Group or Group 16. a. ____________ makes up 20% of air, is used by living things in respiration and provides protection from the sun’s radiation. Oxygen 15OxygenFamily .58 45
19:3 Quick Notes Sulfur • ______________ is used to form sulfides for pigment in paint. • _____________ is used in photocopiers and multivitamins. • _________ & _________ are also in the oxygen group. Selenium Tellurium polonium 46
Group 16 Oxygen Group
19:3 Quick Notes Synthetic F. ____________ Elements—scientists create elements not usually found on Earth; synthetic elements usually disintegrate quickly. 48
19:3 Quick Notes neptunium • Uranium can be made into _____________ which forms plutonium when it disintegrates. • _______________elements have more than _____ protons and are synthetic and unstable. Transuranium 92 49
Synthetic Elements Plutonium also can be changed to americium, element 95. This element is used in home smoke detectors.