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PERIODIC CHART Pages 76
(More electrons could have fit on the 3rd level - 18 - but that electron goes to the 4th level instead- will cover later.) Group 1A Called alkali metals. All have 1 electron on the
Group VIII Noble gases - happy with their electonic structure Group II All have 2 electrons on outer shell.
Group VII 7 electrons on outer shell - Halogen family
Group III
B 3 electrons Group IV C 4 electrons Group V N 5 electrons Group VI O 6 electrons ENERGY SHELLS OR ENERGY LEVELS nucleus
n = 1
n = 2 n = 3
n = 4 Energy level 1 has only 1 subshell
holding 2 electrons ENERGY SHELLS OR ENERGY LEVELS
nucleus n = 1 n = 2 n = 3 n = 4
Electrons are on energy levels or shells. These shells can have subshells or sub levels. Energy level 1 has only 1 subshell holding 2 electrons Energy level 2 has 2 subshells holding 8 electrons Energy level 3 has 3 subshells holding 18 electrons Energy level 4 has 4 subshells holding 32 electrons
MODERN ATOMIC THEORY Pages 73 - 77 REVIEW Electrons are positioned in shells or energy levels around the nucleus. All electrons were created equal, but due to position some have more electrical energy. "Position determines clout." Energy levels are 1, 2, 3, 4, 5, 6, 7 or shells. Subshells are s, p, d, f. "Skinny people drink Fresca." Skinny people diet frequently. Each subshell can hold a fixed number of electrons. Subshell # Electrons s 2 p 6 d 10 f 14 If an "orbital" can hold 2 electrons, how many orbitals does each subshell have
Subshell # Electrons # Orbitals s 2 1 p 6 d 10 f 14
1 H 1s1 ____________2 He 1s2 ____________3 Li 1s2 ____________2s1 ____________ 4 Be 1s2 ____________2s2 ____________ 5 B 1s ____________2s ____________ 2p ______ ______ ______ 6 C 1s ____________2s ____________ 2p ______ ______ ______ Instead of filling up 1 orbital, the electron would rather have more room. 7 N 1s ____2s ____ 2p ___ ___ ___
19 K 1s _____2s _____ 2p ____ ____ ____ 3s ____ 3p ___ ___ ___ 3d ___ ___ ___ ___ ___ 4s ____ Why did the electron go to 4s there were 3d's available?
Let's look at the energy levels below. It takes more energy to go to 3d than 4s, so the 4s fills up before the 3d. 5p ___ 4d ___ 5s ___ 4p ___ 3d ___ 4s ___ 3p ___ 3s ___ 2p ____ 2s _____ 1s _____
19 K 1s2 2s2 2p6 3s2 3p6 4s111 Na 1s2 2s2 2p6 3s14 Be 1s2 2s212 Mg 1s2 2s2 2p6 3s220 Ca 1s2 2s6 2p6 3s2 3p6 4s2Notice that K and Na are in the same vertical column in the periodic chart and both end in s1. Be, Mg, and Ca all end up in s2. That's why elements in the same vertical column in the periodic chart have similar properties. NOBLE GASES Helium has only one energy level and it is filled. 2 He 1s210 Ne 1s2 2s2 2p618 Ar 1s2 2s2 2p6 3s2 3p636 Kr 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6The noble gases end in p6. Energy level 1 s1s2 p1p2p3p4p5p6 2 3 4 Look at neon on the periodic chart 2p6 Argon on chart 3rd row p6 vertical 3p6 Li 2nd row s1 vertical 2s1 Be 2nd row s2 vertical 2s2 N 2nd row p3 vertical 2p3 Na P F Cl O S 1. The maximum number of electrons per orbital is _______________. 2. In the symbol 4p3 a. What is the main energy level? ________________ b. In what set of orbitals are the electrons? __________________ c. How many electrons are represented? ________________________ 3. Fill in the electrons for Ge, Si, Ca, Na 4. If a set of p orbitals contains 4 electrons (p4), how many of these electrons are unpaired? Give the ending Electron Configuration for K Cl K+ Cl- Ag |
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Wednesday, March 21, 2007 01:28:03 PM |