1. Lecture: Atomic Structure intro to: “structure of an atom” http://www.youtube.com/watch?v=TBrJt- 5LHgQ&safety_mode=true&persist_safety_mode=1&safe=active intro to structure of an atom : “Electrons, Protons And Neutrons | Standard Model Of Particle Physics” http://www.youtube.com/watch?v=Vi91qyjuknM&safety_mode=true&persist_safety_mode =1&safe=active You will need a paper copy of the periodic table for this unit and its exam http://www.youtube.com/watch?v=TBrJt- 5LHgQ&safety_mode=true&persist_safety_mode=1&safe=activehttp://www.youtube.com/watch?v=Vi91qyjuknM&safety_mode=true&persist_safety_mode =1&safe=active

2. Draw this:

3. l. Atomic structure A. atom 1. smallest particle of an element which retains its characteristic properties, tear aluminum foil? 2. the fundamental unit of matter (definition?) How does this relate to the atom: ? -building block from which all matter is made: brick house? 3. has NO CHARGE!!! 4. based on Rutherford’s planetary model: radioactive danger symbol: -mostly empty space = a marble in a football coliseum? 5. two regions: ? a) nucleus and b) electron cloud

5. a. nucleus -has two subatomic particles ?: protons and neutrons 1. protons: + charge (battery?), -equals the atomic #: -which defines the element/makes it unique: no other # on the periodic table of elements -has 1 amu of mass: based on the average mass of carbon’s isotopes 2. neutrons: no charge - has 1 amu of mass - #protons + #neutrons = atomic mass 99.999% of an atom’s mass is in the nucleus, E=MC 2 ?

6. Atomic # ? # protons ? Atomic mass ? # neutrons ? # + charges ? # - charges?

7. 3. Nuclear decay: -occurs when the atom is not stable: nucleus breaks apart, many types of decay -occurs when the proton/neutron count is “off”: meaning it varies from norm, thus unstable -a product of the nuclear decay can be an energy emission: radiation, or a matter emission: p or n -Alpha decay: ejects 2 protons and 2 neutrons: ? changes the atomic number and thus the element and mass: -radon gas comes from the decay of U238  thorium  radon  lead (many of our homes in Boulder!) -radon is deadly in your lungs due to the mass emissions (protons=mass!!)

8. -Beta decay: neutron splits into both a proton and electron- it keeps the proton (changes element, why?) and ejecting the electron. Mass stays same, why? -Gamma decay: alpha and beta decay almost always are joined by: emitting very high frequency and high energy waves from the electromagnetic spectrum called gamma rays

9. b. electron cloud - made of electrons moving at almost the speed of light, thus also called the electron cloud: fuzzy images - negative charge - # electrons = # protons, why? (right: because all atoms have no charge) -opposite charges hold the atom together, which particles ? - almost no mass

11. 6. if change # p : change ? if change # n : change ? if change # e : change ? 7. use your periodic table to fill in: PaCa # p?? # n?? # e?? amu??

12. 6. if change # p : change ? if change # n : change ? if change # e : change ? 7. use your periodic table to fill in: PaCa # p9120 # n14020 # e9120 amu23140

13. Examples: Iron: 26 Fe 56 #p, # e, at mass, # neutrons? +1(called?): 26 Fe 56 +1 : #e =? Carbon: 6 C 12 #p, #e, at mass, # neutrons? -1(called?): 6 C 12 -1 : #e =? Potassium: 19 K 39 #p, #e, at mass, # neutrons? +2 (called?): 19 K 39 +2 : #e =?

14. -Bohr atom: like the planetary model, but that is actually incorrect: e- are dynamic and w/ overlapping orbitals 1. electrons occur only at specific energy levels = n, vacuum in between 2. e- farther from nucleus have more energy e- held to atom by a + nucleus (opposites attract), outer ones less so due to e- shielding 3. e- have no specific location w/in shell, only probable occurrence: cloud-like 4. specific # e- occur in each energy level a. maximum # per shell = 2n 2 (n = shell #) shell # 1 = ___ shell # 2 = ___ shell # 3 = ___ shell # 4 = ___

15. Where are shells 6 and 7 ?:

16. -Because of “back filling” and s,p,f,d sub shells, incomplete filling of the energy levels (not maximum) can vary but largely follows this format: -Level 1 = 2 -Level 2 = 8 -Level 3 = 8 -Level 4 = 18

17. -When electrons become energized they become excited and move farther away from the nucleus into outer energy levels: See drawing next page:

18. draw this, note the axis:

19. -Electrons out of their normal energy level are unstable and release energy in the form of light then return to their normal energy level -The color of the light emitted depends on which energy level they “fall back from”: -high energy (outer): has short wave length: violets -low energy (inner): has long wave length: reds -Elements will emit their own different patterns of colors called a spectrum: fire works? -Every element has its own unique color spectrum -The elemental color spectrum is a characteristic property (ie: specific heat, density, solubility, flammability, mp, bp etal)

21. C. Ions: charged “particle” (atom?) 1. atoms can gain or lose electrons 2. when they do they are now charged and thus cannot be called an atom: why ? 3. same # protons as original element/atom 4. different # electrons 5. mass ? 6. + (positive) = cation: gain or lose e-? Na +1, how many electrons? 7. - (negative) = anion: gain or lose e-? Cl -1, how many electrons? 8. NaCl is a neutral compound because: Na +1: lost an electron Cl -1: gain an electron

22. D. Isotopes 1. not all atoms of the same element are identical, ie dogs 2. some have a different # of neutrons, but the atomic # (#protons) are the same, why? 3. what is the charge? 4. thus, the atomic mass is different 5. some isotopes are unstable: decay and emit radiation: radioactive isotopes: C 14 decays into C 12

23. E. Atomic behavior is very unusual and is referred to as quantum theory: Due to their small size, they no longer can be explained by classic physics, instead their values are restricted to specific amounts: energy and momentum F. Along the same lines as quantum theory is the uncertainty principle: due to its dynamic state, subatomic particles cannot be fully observed and described simultaneously, thus there is a degree of uncertainty of the particles’ attributes: time, position, energy and momentum