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Unit EQ: How is Periodic Table arranged?. Warm-up 9/27/10 What does the word periodic/period mean to you? Open book to p158 Get 3 colored pencils off education table. repeating in a predictable pattern. Unit EQ: How is Periodic Table arranged?. Three main classes of elements
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Unit EQ: How is Periodic Table arranged? Warm-up 9/27/10 • What does the word periodic/period mean to you? • Open book to p158 • Get 3 colored pencils off education table repeating in a predictable pattern
Unit EQ: How is Periodic Table arranged? Three main classes of elements Then within those 3 18 groups (columns) 7 periods (rows) Metal metalloids non-metals
Unit EQ: How is Periodic Table arranged? Mendeleev – 1869 (russian) arranged elements according to atomic mass He left blanks in table –predicted presence of unknown elements – Awesome! Lothar Meyer – a little late Moseley – 1913 (british) made slight change and arranged by atomic number
Unit EQ: How is Periodic Table arranged? EQ: Why is Hydrogen in with Alkali metals? Warm-up 9/28/10 1) What is group 2 called? Group 3-12? 2) What temp. does water boil? freeze?
Unit EQ:How is periodic table arranged?Subatomic particles? Warm-up 9/29/10 • How many protons, neutrons and electrons does Carbon 12 and Carbon 14 have? • Test Next Thursday Oct 7th on History and parts of atom Read and take notes on chapter 4 and section 6.1
Calculating subatomic particles • Atomic number (Z)= # protons = # electrons • Atomic Mass (A)– often average atomic mass equal to # of protons plus # of neutrons in nucleus • Mass number = protons + neutrons for specific isotope • Isotope – atom of same element with different # of neutrons and therefore different mass numbers.
Video On History of Atom 9/29/10 • Einstein and Bohr fight over atomic theory • Schrodinger and Heisenberg throw down
Atomic Theory Democritus 400BC– Indivisible and indestructible Dalton 1803– 1. Indivisible (wrong because fission –splitting atoms and subatomic particles) 2. Atoms same element identical- (wrong b/c Isotopes – atoms same element different mass) 3.combine in simple whole number ratios 4. React by combining, separating and rearranging Goldstein 1886 - proton Thomson 1897- cathode ray tube- discovered electrons – Plum pudding model
Atomic Theory Cont. Rutherford 1911– Gold foil experiment Discovered the nucleus and most of atom is empty space Bohr 1913– electrons occupy fixed orbits around nucleus and can jump up or down by gaining or losing energy Millikan 1916 – found the quantity of charge of electron and its mass 1/1840 of hydrogen atom Chadwick 1932– neutron
Current model derived with crazy Math Quantum Mechanical Model also electron cloud model - dense central nucleus surrounded by electrons in orbitals- areas of high probability to find electron Heisenberg uncertainty Principle- can not tell the position and velocity of an electron simultaneously
Unit EQ: Atomic History? EQ: What is the atom made of? • How can you tell what a star is made up of? • Who helps us figure this out? • Test/Quiz Next Thursday Oct 7th on History and parts of atom Read and take notes on chapter 4 and section 6.1