求解答案是否正確

Multiple-choice questions: (70 points) write the letter of statement that is not true: 1. A.B.U The Drude Model: (a) It is a classical approach using concepts from the kinetic theory of gases. (b) A relaxation-time approximation is used where the probability of collision is l/t. (c) No forces act on the electrons in between collisions. (d) It predicts accurately the electronic heat capacity of metals. 2. The Sommerfeld Model: (a) The crystal potential is replaced by an average Coulomb potential. (b) The separation of states is so close that a continuum model can be applied. (c) The electrons are highly localized due to a strong crystal potential. (Q) The energy of the highest occupied state at 0 K is the Fermi energy. 3. Density of states in k-space, N(k): (a) N(k) is determined by the boundary value conditions. (b) For lattices in any dimensions, N(k) is constant in k-space. (C) N(k) depends on the direction and magnitude of k. (d) It is directly proportional to the volume of the crystal. E影響, c 4. The Fermi surface of a metal: (a) is responsible for many of the transport properties of the metal, (b) depends on the nature of the chemical bonds, (c) is always a sphere, (d) can involve mixing of electron orbitals. ✓ 5. The conductivity of a material () increases with the mobility of its carriers, (b) increases with the density of carriers, (C) it is inversely proportional to the energy gap. cogu changes with temperature. 6. BID Plasmons: (a) They are an important characteristic of the Sommerfeld electron gas model. (b) Plasmons occur spontaneously in metals. (c) They are related to charge density oscillations. (d) The Plasmon energy is typically of the order of 10 eV. The Fermi energy Ef in intrinsic semiconductors 8) is usually close to y E, at OK (b) it ACiD. can increase or decrease with temperature depending on the ratio of hole and electron effective masses, (c) it represents the point at which the probability of occupation is 12, even though there may not been any states with that energy, (d) its value relative to the electronic bands must remain unaffected in the presence of defects or interfaces.

謝謝

Equilibrium constant calculations often have as much as 5% error X in them because (A)molar concentration and pressures are often used. (B)there is experimental error involved in measure K. (C)the chemical activity should be used. (D)approximation are often used to solve very difficult calculations. (E)all of the above. 【83 中興B)

想問5-9 該怎麼算 ？ 第一個選項就可以了 謝謝

the sample size? (b) 250 ing? 211% -6208 *(a) 500 mg. *(c) 150 mg. Xloo to 10.4 ) X100% =0108 / mg 506 016 5-8. A method of analysis yields masses of gold that are low A by 0.4 mg. Calculate the percent relative error caused ylvila by this result if the mass of gold in the sample is 625 mg.6 20 (d) 70 (c) Dit X 106% 8.6 5-9. The method described in Problem 5-8 is to be used for the analysis of ores that assay about 1.2% gold. What minimum sample mass should be taken if the relatived) error resulting from a 0.4-mg loss is not to exceed *(a) -0.1%? (b) -0.4%? 5 * (c) -0.8%? (d) - 1.1%? Slastin 0 (14)。

只有氧是不規則的命名嗎？ Tetroxide vs tetraoxide Pentoxide vs pentaoxide PCl5 後面Cl 就是 pentachloride

6 机 BLE 2.6 | Prefixes Used to Indicate Number im Chemical Names U選4 7)o7o- g- 7二 Numberindicated 1 7efrg- 2e77o- Agexog- 7epfg- Ocfg- 7o7g- 選和os和 eu |,, decg- INTERACTIVE EXAMPLE 2.8 SOLUTION JPHABnEB 呈_Atomsg, Miolecules, and Ins consider the names ot the s will no To see how these Tules apply, 沿 同 lent compounds formed by nitrfgg 時 as tematic Name 了 同 loxi Nitrous oX1ce de 。 imitrogen InonoX1 1 9 ii monoxide NI 時 4 NO Nitrogen N os Dinitrogen TioX1 同 Noo, Dinitrogen tetIOX1 Noo Dinitrogen pentoxi 2 avoid awkward pron that to hen the element beglns Wtt 7oO/ dinitrogen tetrdox ng examples fthe prefiX trogen tetroxide, tt their common names- esystematic names to Notice from the precedi often drop the final ? % 20 example, N204 1S called dinlt called carbon monoxide, 7 carbo Some compounds are always Te are water, ammonia, and hydrogen pe H2O2 are never used. n monoox1l ferred to by roxide- Th Naming Type 山 Binary Compounds 1. Name each of the following compounds: a. ,PCD DBGIG MS 09 2. From the following systematic nameS, Write the formula for ea a.。 Sulfur hexafluoride b. Sulfur trioxide c.。 Carbon dioxide 1 Formula Name a. PCl Phosphorus pentdehloride Be Phosphorus trichloride c. SO2 Sulfur dioxide 2. Name Formula a.。 Sulfur hexafluoride SFe b.。 Sulfur trioxide SO ce. Carbon dioxide CO

想問RC circuit 中 charge 跟 discharge 如附圖內的等式是怎麼得出的呢？ 思考了一段時間也上網查過了

The sum ofthe potential difference across the capacitor and resistoris away Constant, so Vc 十 MRg 三委. As charge flows to the Capacitor, the potential difer: ence across it increases, which means that the Potential difference across及誠 the current through the circuit, must decrease. In this circuit, the current /當 Credyey the charge on the capacitor, and therefore 7 二 十ZO/2/. As the currit decreases, we expect the Tate at which the capacitor charges also to decrease When the potential difference across C Teaches 儿, the potential difference acr0S AR 1s zero: The current Stops flowing, and the charge on the capacitor ha5出 maximum value Oo = Cx, When 7 = +Z0/dr is used in the loop rule, we find

想問問看大家這題普化😭

Crjticat Thinking ) The text states that “the pKa of 和e weak acid selected for the puffer shoujd be as close as pos- sible to the desired pH.”What 1 the pK, is not close to the desired PH? What is the problem with choosing such a weak acid used um 出e buffer?

普化問題 麻煩大家ㄌ🥺🥺

Criticat Thinking ) The text states at “the pKa ot 仙e weak acid selected for the puffer shoujd be as close as pos- siple to the desired pH.” What 1 出epKa is not close to the deslired PH? What is the problem with choosing such a weak acid used 症 出e buffer?

125怎麼算

plus o辣 1.0 kg concen Cacid (98凶 日SO04 by mass誰 和 the 過 128。 Hydrogen peroxide 1S used as a cleansing agent in the freat- 呈卻 ma ent Of cuts and abraslons for several] reasonsS. It is an Oxidiz- : e Ing agent that can_ directly kill many microorganisms: 1 全 decomposes on contact With blood, releasing elemental oxy- d. gen gas (which inhibits the growth of anaerobic microorgan- 1Sms); and it foams on contact with blood, which provides a 1 診 1 ed in | cleansing action. In the laboratory, small duantities of hydro- cop as gen peroxlde can be prepared by the action of an acid on an 兒 時 alkaline earth metal peroxide, such as barium peroxide: We Baoy() + H2 What mass of hydrogen peroxide should result when 1.50 g barium peroxide is treated with 88.0 mL hydrochloric acid solution containing 0.0272 g HCl per mL? What mass of

求圈起來的幾題

補史名www asftrppfysfts 600) For Thoughtand Diseussion tneuish the Aristotelian and Galilean/Newtonian views ofihe ball bounees ofrawall with the same speedithad beforeithit Wall Has its momentum changed? Hasaforoe acted on the 2 Has aforee acted on the wall? Relate your answers to New aws of motion ten use the term "inertias to deseribe human sluggishness 5this usage related to the meaning ofFsinertiae in physics? does aceiling fan continue to rotate even after you have vitched it ofP? Wek erashes into a Stalled cear A student trying to explain the es ofthis event claims thar no forees are involved: the car Tin the way”so itgot hit Commen foot astronaut kicks a ball, hard, across aspace station balls apparent weightlessness mean he astronauts toes 下avity on Jupiters moon Io is one-fifth that on Would happen te your weight and to your mass if nIo? tis the direcetion of momentum oFamoving body? Does it Fthe body: plane aceelerates down the munway, you take your keys r poeket and suspend them by a thread. Do they hang force from the chairon you. iir? Hnot, what forees are fxerrisesaned Problems 85 $ 還2620Groeoeoeardaoeos WiA poaor Wonoeno0 Op ir oa 20。 Staring frorm rest and undergoing constan acceleratiom,a920-kg ar covers 410 min $.15 8. Find the foree on the car 21 dropping dontest, a student encatses am 83-g cgg in large Styrofoam block. fs g emn'texceed 2.0N and 計the bloek hits the g pow mueh must the Styror jompress on impaet) Note: The aceelei assoeialed with stOppi gravity while the Styrofe the ground. 22. Inatront-end collision, a 1400-kg car with shockzabsorbing bump: ems can withstand amaximum force of 75kN before damage Gccurs: Hthe maximum speed foranondamaging collision is 9.0 kmzh, by Bow much must he bumper be able to move relative to the car? section 4.4 The Force ofGravity 23。 Show that the units of aceeleration can be written as N/kg- Why doesitmake sense to give gas 9.8 N/kg when talking about imass and weight? 24. Your spaceship crashes on one of the Sun's planets, Fortunately 上 the ship's scales are intact and show that your weightis 680 N.H your mass is 58 kg, where are you? (imr: Consult AppendixEE) Your friend can barely lift a 35-kg concrete block on E: massive ablock could she lift on the Moon? 26 Acereal box says "net weight 350 grams” Whats the actual Weight ta in SLunits and (b) in ounees? 27. Youre asafety engineerforabridge spanning the U,S-Canadian border. U.S. speeifications permit a maximum load of 10 tons What load iimit should you speeify on the Canadian side. where welght is given in kilograms? 28.。 The gravitational acceleration atthe lntermational Space Stations altitude is about 91凶 oFits surface value. Whats the weightofa 64-kg astronaut atthis altitude? ection 4.5 Using Newton's SecondLaw A 50-kg parachutist deseends atasteady 40 km/h. What foree does air exert on the parachute? 30, A 960-kg motorboat accelerates away from adock at2.1 m/s Its propellerprovides a3.9-kN thrust force. What drag force does the water exert on the boat? An elevator aceelerates downward at2.4 ms. What force does the elevator's floor exertona52-kg passengery 32. At 560 metric tons, the Airbus A-380 is the World's largest air- liner Whats the upward force on an A-380 when the plane is (am flying at constant altitude and (b) aceelerating upward at 15m/s2? 33. Yourre an engineer working on Ares 1 NASAs replacement tor the space Shuttles. Performance speces call for afirst-stage TOcket Gapable ofaccelerating atotal mass 0f 600 Me vertically ftom Testt0 7700 km in 1.7 min. Youre asked to determine tbe re- quired engine thrust (force) and the foree exerted ona79-kg as- tronaut during Tiftoff. What do you Teport? 34. You step into an elevatorand itacceleratesto adownward speed gfF8.8 mAS in 2.4 5 Quantitatively compare your apparent weight during thistime with youracetual weight, 44.6 NewtonsThirdLaw ional foree does 3 5600-kg elephant exer 必 63. she jumps ofta140-emhi過台 人 rdheras she falls?

請問一下，第45題怎麼算

96d nt” Chemieal EdUUDT LT 人 說 1 ction below ata certam 1 全 同 同 equilibrium ee 說 ii [Ho2] 三 0.0500 TE 、 ipid container are 總 人 2 抽 Ho(g) + 到(tg) 三一 2HF(g) /@巡 > 1 / 1 語全 全胸 : iibri mmIXtUure, 0 2 於 了 人 0.200 mole of Fz is added to this 1 gquilib- thee 2 caJcuJate the'corcentrations 9f a11 gases 1 )。 入 rium is reesfablished- 2 只汪 人 和 沿之 / (9 1100 K, 及p 0.25 for the following reactlon 1 三入 3 、 一一 所 全生 /4 2SQ23(g) 十 Qz(g) 二二 250O3(9 du Ttbe 選娘 an ial pressures of 502, 人2 te 全 了Cajculate the eduilibrium Partial pressure 人 同 葬 也62人 5O3 produced 自om an initfaL_mixrure In 8 oo 三 Po 王 0.50 atm and Pso, 三 0. 2人 三人 1和 宅及林用 生 ” 46. At 22002C 肥 三 0.050 for the reaction 2509 4 2 yy2(9) +O2(g) =二 2NO() 的 What js 和the partial pressure of NO at equilibrtum as 人選 9 suming he N2 and O2 had initial pressures of 0.80 atm 全 // -彈d 0.20 atm, respectively? @ / 32 5 相/ 和pe )f reactiOn_ we wi study is that having a very 汪 補- 六sma上有value (K<< 1 Solving for equilibrium concen- 一條0說人 frations jm an eduilibrium problem usually requires many mathematica| operations to be performed. How- 說 和 even the math involved in solving edquilibrium problems 。。 %6 2 Ina D6909 , for feactions having smal| K values (K << 1) 1s simpli- 527- fied. Whatassumption js made when solving equilibrium 1 Concentrations for reactions having small 太 values? 534 Le 台 戰 Whenever assumptions are made, they must be checked ler ? (吃 hdiry np general the 59 rule> is used to check t cd 旨 Me Vaudlty of assuming thatx (or 2x, 3x, and so on) is ga 只 sma compared to some number Whenx (or 2x, and so 1 less than 和