Chemistry PDF Notes

 Week #1 : that has matter-anything · mass and occupys space Universe · energy anothe...

 Week #1 : that has matter-anything · mass and occupys space Universe · energy another form of - existence = responsible for transformation, transfer , and "Keeping things together" for Chemistry-study of matter and · energy Shape - composition A) form of structeee matter > structure I property properties r physical change B transformation ~ schemical change Genergy existence of matter > transformation of matter · ex: 1 9cm. > m · = 0 019m. Weekl : · eX : 1 90cm. x X = 1 90. xo - 1 90x00 =1 90X.. m = 1. 42x10Coatoms 256 pr  Week 2 : ~ turofMatter- microscale (um-mm) Nanoscale (pm nm) - particles-general name for structural units of a substance matenice o pure substance mixture Yes ? No uniform ? yes No J separable - F 7 element compound heterogeneous homogeneous element-pure substance · made of identical particles that cannot be decomposed into substances with simpler structure compound-pure substance that decomposed · can be into elements or structurally simpler compounds mixture - 2 or more substances mixed together with no chemical reaction occurring homogenous-uniform · mixture heterogeneous nonuniform mixture · - · · ⑨ ⑧o " · ⑳ · &.o 00 00. ⑧ ⑧ 00 ·o 8 · O mixture of molecular compound molecular compounds element molecular element Atomic ~ Theory : · law-description of what always happens in the same conditions theory explanation of · - what happens  Week #2 ~Massi Conservation of · matter is neither created nor destroyed · ex : Na(s) + ((z(g) - NaCI(s) 11 19 69 + 2 9g =. 7g.. Definite Proportions : · element ratio in one compound same elements combine in the same proportion to compound · always make a eX: · con · atoms ratio= mass ratio also remains constant · ~ Multiple Proportions : ratio to element ratio in 2 different compounds When the 2 ratios in which the same 2 elements combine to form L · comparing different compounds , one ratio is a whole multiple of the other eX : · mass ratio : (o (0z = = s Atomic Theory : 1) all atoms of an element have identical properties 2) atoms combine in whole-number ratios to form compounds 3) atoms of one element cannot change into atoms of another element 4) When identity just the way they forming different compounds atoms do not change their bind with other atoms  Week #2 : Particles Within the Atomi - ~ aka subatomic particles particle Symbol Charge rel massActual mass ·. 1/1836 9 11 x 10-20 ! electron e-. proton pt I 1. 674x1029 neutron N ⑧ I 1 675 x. 10-2 g ~ Atomic Number Sand : # protons (pt) = #electrons (e) ° A · n = - z by has # Atomic # (p + + n0) (protos) Kiameter : O c ⑳ ⑨ J ⑧ Do & ↑ e - - u nucleus proton/neutron quark electron at om ~ 10-cm ~ 10 cm >10-cm 4 10 - Cm ~ 10-8 im totopes : · atoms of the same element (same2) but different mass number (A) · same number of pt same number of e- · · different number of no aut · Notation : was a zen #Y  Week #2 : Average Atomic Massi - Natural (Percent) Abundance : · the of certain isotopes natural sample of element percentage in a an. · # of isotope atoms = Y Atoms of isotope total of that element 100 atoms of that element # of percent of isotopes = isotopes X100 total of atoms of that element ex: relative atomic mass · average atomic mass of Bi "B (% 1) ("Batomic mass)+ (% "B)(13 atomic mass) " 19. 91 %; 10 129 amu. "B 80. 09 %; 11 0093 amu. T 100. 00 'B < 19. 91 (10 0129). = 1. 994 amu 19 91 100 - 1 994. + : 80 09. "B 80. 09 (11 0093). = 8 817. amu 8 817. 100 10. 81 1 a mu The Mole : ona · - · avogadros number= 6 02 x. 102 · ex: 63 5 glnd (u. < 320g sample mass moles particles 63 I. 59 x Xma 320g , 320 = 63 55x X = 5 03.. mo (u -X mola/ mass X6 02x1023. Week #3 : energy ~ as Electromagnetic Radiation : electromagnetic radiation (EMR) form of energy transport - Oscillating perpendicular electric and magnetic fields traveling through at · , , space the same rate , in a wavelike motion · wavelength (X) = distance between repetitions of the sinusoidal shape either full crest, through · a , or a cycle repeats m , cm hm... · , · I wavelength I wavelength 1 cycle I 2 cycles Week #3 : frequency (V). # of complete cycles passing a fixed point/unit of time · unit = T Hertz (Hz) 1/s = = 5 I second I I F! I cycle zcycle' a cycle' frequency = - 3 3Hz cycles : per 35 second Shorter time-higher frequency · wavelengths complete cycles per unit of = more Speed-distance traveled by a point of a wave (m) / time (s) faster fixed point/second · waves= greater speed more crests pass a < higher frequency - shorter wavelengths · c= vX · c= speed of light (m/s or mst) = Frequency (1/5 or s or Hz) A wavelength (m) · = * When the speed of does not wavelength decreases, the frequency increases so , the a wave change as long as it travels through the same medium Week3 : vx mv cx · ex : c = = 589nm x 10 - 2 = 5 89x10 "m. v= (3 00. x 100m/s)/(5 89x10- m). ° 3 00x10 = xi. * 509x10'sst = 0. 509x10 X 10 s = 0. = 5 09X10's. - · electromagnetic spectrum - distribution of X(V) of EMR emitted or absorbed by matter · energy decreases from gamma rays (highw , Short 1) to radio wares (low V long X , higher v = more energy The - Electromagnetic Spectrum : is absorbed and emitted in chunks that correspond to different wavelengths · energy planck's theory Max Planck : electromagnetic radiation is quantized can be transferred only in certain amounts (packets or quanta) quantum-smallest amount of that transferred in shot energy can be one E is directly proportional to frequency Equantum hu = hc/X · = · h planck's = constant = 6 626. x 10"Js photoelectric effect- emission of e by metals when light of certain E(worA) interacts with their surface the of light that "hits" the be than the opposite charge attraction · energy e must greater between the nucleus and the et light of certain wavelength (frequency or energy) Kicks electrons out of metal atoms proof that light sometimes behaves as a stream of massless particles = photons photons "hit" e from · that atoms at the surface and transfer metal energy : E Eabsorbed · released -Ephoton ** Eelectron Albert Einstein : only a certain "pulse" of light can eject electrons ,so the electromagnetic radiation doesn't always travel as stream of continuous energy photons but as a packets of a ware , tiny Photon-unit (quantum) · of energy within the electromagnetic radiation (simplistically, a photon would correspond to a number of full wave cycles) Einoton hu = nc/X · = h planck's 626x10-345s · = constant = 6. some experimental observations are better explained by considering light Cradiation) as waves , some of "massless particles" by considering radiation as photons - a type Week #3 : Homework & X=3 00 x10 ms 464x =. = 0. 6 46x10s. 4. 64x10 3 00x100m/s - 0 00594x10". = >. v = 505x10-9 5 94x1014. Ephoton = hr > (6 626x10**3)(v). 7 01. x +9 10 -= (6 626x103" (s)(v). v= 7 01x10. -" - = 1. 06x10'. 626x16'3"S 6 Ephoton hc = < (6 626x10 Ts)(3 00x100m/s). **. = O. osusxio 365x109m 5. 45x10-19- ↳ RH( 1 097x10'mi)it - ) = 1. & + = 1. 097x10m+ (T -) X = 1. 097x10'm" (1-0 04). = 1 097x10'm". (0 96). = 1 05312 x 10 m+. I 9496x10m X = 1 05312x103m = 0. S. - 9 496x10. hcRh() E = = (6 626x10 345s)(3 00 109 (1 097 101) (0 96). -. x. x. = 2. 09x10- Week #3 Photectron o , photo electric effect : light emission ONLY If E incoming binding E photon line spectrum-elements emit never white only certain colors , light thermal energy(heat) - also produces emission of light as specific colors for different elements ~ Spectroscopy Explained mic : hydrogen emission spectrum - appears when Hatoms are given extra energy , such as heat or electrical energy H alpha line 656 hm Hatoms with extra energy emit the energy excess as light of different energies (wavelengths) in the VIS range hydrogen absorption spectrum - appears when light is passed through cold Hatoms Hatoms (wavelengths) the · absorb energy as absorbed light of different energies continuous light spectrum will lack the same colors elements spectra "fingerprints" of · are the elements the emission lines appear at the same & as the absorption lines emission absorption and do not occur continuously elements spectra-experimental proof for the fact is not emitted absorbed but packets that energy or continuously in  Week #3 Bohr's Idea · - Energy conservation : orange photon absorption : emission: nucleus her energe · orange photon M. incoming photon is absorbed by the Atom electron · excited State ↑ lower energy level · ·3 lowest energy leva · red photon y proton cowemitted nucleus lowest energy incoming level red photon photon is absorbed by the Atom Kinetic · energy absorbed as light turns into energy of the electron and Vice versa. photoelectric effect - c absorb photons energy to totally overcome the attraction of the nucleus ; after electron emission , the atom becomes ion electron transitions-e absorb light energy (photons) to partially overcome the attraction of the nucleus and more to a higher energy level ; the atom does not lose e any the transition happens · when the photon energy equals the difference between two energy in the atomi only levels DE Ephoton Ez-E · = = , electron light energy converts to electron energy Ez W DE electron E photon ↑ Er the the electron loses falls to the lost energy becomes light · reverse process : energy and a lower energy level ; emitted (Photons - DE = (E - E , ) = E photon Ez A SE electron un # E , Week #3 electron levels have transmitted are quantized can only certain values just like energy electromagnetic = as energy , warks · E = -2 179x10. T - - (ni) n = 1 , 2 , 3.... position of to = positive integer that indicates the an energy level relative Rydbergs constant the nucleus the free electrons (release) · lose Kinetic the nucleus attracts them to form an atom the lost energy when. Kinetic energy converts to binding energy (potential energy expressed as electrostatic attraction to the nucleus electrostatic attraction · opposite attraction charge = A Mary of Bohr Model : · Ephoton = Lelectron light converts to extra Kinetic energy of the electron t absorption of photons by (released) (absorbed) the atom E = hv = h(x) Photon De = -2. 12ax10" (ni -i) -SE Electro Epod