NOTES. Name: Date: Topic: Periodic Table & Atoms Notes. Period: Matter

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1 NOTES Unit: Tpic: Peridic Table & Atms Ntes Name: Date: Perid: Matter Atmic Structure The term matter describes all f the physical substances arund us. Matter is anything that has mass and takes up space. Atms: Building blcks f matter. Atms are made f even smaller particles called prtns, neutrns, and electrns. Prtns: Psitive electric charge (+) Neutrns: n charge; neutral (0) Electrns: negative electric charge (e-) Mve rapidly arund nucleus. An atm cnsists f a nucleus surrunded by ne r mre electrns. Nucleus: center f atm; grup f neutrns and prtns. In an atm the number f prtns equals the number f electrns. The charges balance, making the atm neutral. Bhr Atmic Mdel Bhr mdel: mdel that shws all f an element s electrns mving in specific layers, r shells, rather than randmly.

2 Tpic: Peridic Table & Atms Ntes Valence Electrns Electrns nly in the uter shell f an atm Lewis Dt Structure Shws hw many electrns are in the valence shell f each element accrding t the ctet rule. Octet Rule Octet Rule: Atms tend t gain, lse, r share ne r mre f their valence shell electrns t achieve a filled uter electrn shell. Elements Element: a substance that cannt be divided int ther substances. An element can be identified by the number f prtns in the nucleus f its atms. Atmic number: the number f prtns in the nucleus. Atmic mass: sum f the prtns and neutrns in the nucleus.

3 Tpic: Peridic Table & Atms Ntes Elements f the Peridic Table Elements f the peridic table can be divided int three categries: Metals Nn-metals Metallids Prperties f Metals Prperties f Nn-Metals Prperties f Metallids Metals are gd cnductrs f heat and electricity. Metals are shiny. Metals are ductile (can be stretched int thin wires). Metals are malleable (can be punded int thin sheets). A chemical prperty f metal is its reactin with water which results in crrsin. Nn-metals are pr cnductrs f heat and electricity. Nn-metals are nt ductile r malleable. Slid nn-metals are brittle and break easily. They are dull. Many nn-metals are gases. Metallids (metal-like) have prperties f bth metals and nnmetals. They are slids that can be shiny r dull. They cnduct heat and electricity better than nn-metals but nt as well as metals. They are ductile and malleable.

4 Tpic: Peridic Table & Atms Ntes Families Clumns f elements are called grups r families. Elements in each family have similar but nt identical prperties. Fr example, lithium (Li), sdium (Na), ptassium (K), and ther members f family IA are all sft, white, shiny metals. All elements in a family have the same number f valence electrns. Perids Each hrizntal rw f elements is called a perid. The elements in a perid are nt alike in prperties. In fact, the prperties change greatly acrss even given rw. The first element in a perid is always an extremely active slid. The last element in a perid, is always an inactive gas.

5 Tpic: Peridic Table & Atms Ntes What des it mean t be reactive? We will be describing elements accrding t their reactivity. Elements that are reactive bnd easily with ther elements t make cmpunds. Sme elements are nly fund in nature bnded with ther elements. What makes an element reactive? An incmplete valence electrn level. All atms (except hydrgen) want t have 8 electrns in their very utermst energy level (This is called the rule f ctet.) Atms bnd until this level is cmplete. Atms with few valence electrns lse them during bnding. Atms with 6, 7, r 8 valence electrns gain electrns during bnding.

6 Tpic: Peridic Table & Atms Ntes Slids Particles are packed tightly. Very lw energy Definite shape. Definite Vlume. Examples: rck, pencil, cncrete Liquids lsely packed. Have medium energy levels Definite Vlume. Has n definite shape. Examples: water, il Gas Mve freely. Have a lt f energy N definite vlume. N definite shape. Examples: xygen, helium Plasma N definite vlume. N definite shape. Plasma is a lt like a gas, but the particles are electrically charged. Extremely high energy levels Examples: nen lights, light in flrescent light bulbs. Energy determines the state!

7 Tpic: Peridic Table & Atms Ntes When energy is added, particles mve faster! When energy is taken away, particles mve slwer!