Multiple ChoiceCalculate the energy (in nJ) of a photon emitted by a mercury lamp with a frequency of 6.88 x 1014 Hz.1329views1rank3comments
Multiple ChoiceA light ray has a wavelength that is 835 µm contains 6.32 x 10-3 J of energy. How many photons does this light ray have?1006views4rank3comments
Multiple ChoiceHow much energy (in kJ) do 4.50 moles of photons contain at a wavelength of 705 nm?927views2rank1comments
Textbook QuestionWhat is the energy (in kJ) of one mole of photons of ultraviolet light with a wavelength of 85 nm? (LO 5.3) (a) 1.4 * 10-6 kJ (b) 1.4 * 103 kJ (c) 2.4 * 1014 kJ (d) 2.4 * 10-15 kJ1395views
Textbook QuestionWhere does the energy come from to evaporate the esti- mated 425,000 km3 of water that annually leaves the oceans, as illustrated here? [Section 18.3]315views
Textbook QuestionThe dissociation energy of a carbon-bromine bond is typically about 276 kJ/mol. (a) What is the maximum wavelength of photons that can cause C-Br bond dissociation?1342views
Textbook Question(b) Use the energy requirements of these two pro- cesses to explain why photodissociation of oxygen is more important than photoionization of oxygen at altitudes below about 90 km.519views
Textbook QuestionIf human height were quantized in 1-cm increments, what would happen to the height of a child as she grows up: (i) the child's height would never change, (ii) the child's height would continuously increase, (iii) the child's height would increase in jumps of 6 cm, or (iv) the child's height would increase in 'jumps' of 1 cm at a time?461views
Textbook Question(a) Calculate the energy of a photon of electromagnetic radiation whose frequency is 2.94 * 1014 s - 1.830views
Textbook Question(b) Calculate the energy of a photon of radiation whose wavelength is 413 nm.1039views
Textbook Question(c) The laser pointer emits light because electrons in the material are excited (by a battery) from their ground state to an upper excited state. When the electrons return to the ground state, they lose the excess energy in the form of 532-nm photons. What is the energy gap between the ground state and excited state in the laser material?2511views1rank
Textbook QuestionAn AM radio station broadcasts at 1000 kHz and its FM partner broadcasts at 100 MHz. Calculate and compare the energy of the photons emitted by these two radio stations.905views
Textbook QuestionOne type of sunburn occurs on exposure to UV light of wavelength in the vicinity of 325 nm. (d) These UV photons can break chemical bonds in your skin to cause sunburn—a form of radiation damage. If the 325-nm radiation provides exactly the energy to break an average chemical bond in the skin, estimate the average energy of these bonds in kJ>mol.1888views
Textbook QuestionOne type of sunburn occurs on exposure to UV light of wavelength in the vicinity of 325 nm. (c) How many photons are in a 1.00 mJ burst of this radiation?920views
Textbook QuestionAlcohol-based fuels for automobiles lead to the production of formaldehyde (CH2O) in exhaust gases. Formaldehyde undergoes photodissociation, which contributes to photo- chemical smog: CH2O + hn ¡ CHO + H The maximum wavelength of light that can cause this reac- tion is 335 nm. (b) What is the maximum strength of a bond, in kJ>mol, that can be bro- ken by absorption of a photon of 335-nm light?459views
Textbook QuestionCalculate the energy of a photon of electromagnetic radiation at each of the wavelengths indicated in Problem 39. a. 632.8 nm (wavelength of red light from helium–neon laser) b. 503 nm (wavelength of maximum solar radiation) c. 0.052 nm (wavelength contained in medical X-rays)2412views1rank1comments
Textbook QuestionCalculate the energies of the following waves in kilojoules per mole, and tell which member of each pair has the higher value. (a) An FM radio wave at 99.5 MHz and an AM radio wave at 1150 kHz921views
Textbook QuestionCalculate the energy of a photon of electromagnetic radiation at each of the frequencies indicated in Problem 40. a. 100.2 MHz (typical frequency for FM radio broadcasting) b. 1070 kHz (typical frequency for AM radio broadcasting) (assume four significant figures) c. 835.6 MHz (common frequency used for cell phone communication)2745views
Textbook QuestionA laser pulse with wavelength 532 nm contains 3.85 mJ of energy. How many photons are in the laser pulse?7558views4rank
Textbook QuestionA heat lamp produces 32.8 watts of power at a wavelength of 6.5 µm. How many photons are emitted per second? (1 watt = 1 J/s)3036views
Textbook QuestionDetermine the energy of 1 mol of photons for each kind of light. (Assume three significant figures.) a. infrared radiation (1500 nm)2163views
Textbook QuestionWhat is the energy of each of the following photons in kilojoules per mole? (a) v = 5.97 * 1019 s-1 (b) v = 1.26 * 106 s-1 (c) = 2.57 * 102 m475views
Textbook QuestionHow much energy is contained in 1 mol of each? a. X-ray photons with a wavelength of 0.135 nm b. g-ray photons with a wavelength of 2.15 * 10-5 nm3353views2comments
Textbook QuestionAccording to the equation for the Balmer line spectrum of hydrogen, a value of n = 3 gives a red spectral line at 656.3 nm, a value of n = 4 gives a green line at 486.1 nm, and a value of n = 5 gives a blue line at 434.0 nm. Calculate the energy in kilojoules per mole of the radiation corresponding to each of these spectral lines.1655views1rank
Textbook QuestionThe rate of solar energy striking Earth averages 168 watts per square meter. The rate of energy radiated from Earth's surface averages 390 watts per square meter. Comparing these numbers, one might expect that the planet would cool quickly, yet it does not. Why not?1859views
Textbook QuestionUltraviolet radiation and radiation of shorter wavelengths can damage biological molecules because these kinds of radiation carry enough energy to break bonds within the molecules. A typical carbon–carbon bond requires 348 kJ>mol to break. What is the longest wavelength of radiation with enough energy to break carbon–carbon bonds?3991views2rank
Textbook QuestionThe human eye contains a molecule called 11-cis-retinal that changes shape when struck with light of sufficient energy. The change in shape triggers a series of events that results in an electrical signal being sent to the brain that results in vision. The minimum energy required to change the conformation of 11-cis-retinal within the eye is about 164 kJ>mol. Calculate the longest wavelength visible to the human eye.5678views2comments
Textbook QuestionIonization involves completely removing an electron from an atom. How much energy is required to ionize a hydrogen atom in its ground (or lowest energy) state? What wavelength of light contains enough energy in a single photon to ionize a hydrogen atom?1798views1comments
Textbook QuestionThe concentration of H2O in the stratosphere is about 5 ppm. It undergoes photodissociation according to: H2O1g2 ¡ H1g2 + OH1g2 (b) Using Table 8.3, calculate the wavelength required to cause this dissociation.466views
Textbook QuestionIf a sample of calcium chloride is introduced into a nonluminous flame, the color of the flame turns to orange ('flame test'). The light is emitted because calcium atoms become excited; their return to the ground state results in light emission. (b) What is the energy of 1.00 mol of these photons (a mole of photons is called an Einstein)?2983views
Textbook QuestionThe watt is the derived SI unit of power, the measure of energy per unit time: 1 W = 1 J>s. A semiconductor laser in a DVD player has an output wavelength of 650 nm and a power level of 5.0 mW. How many photons strike the DVD surface during the playing of a DVD 90 minutes in length?2639views
Textbook QuestionA 5.00-mL ampule of a 0.100-M solution of naphthalene in hexane is excited with a flash of light. The naphthalene emits 15.5 J of energy at an average wavelength of 349 nm. What percentage of the naphthalene molecules emitted a photon?1065views1rank
Textbook QuestionA laser produces 20.0 mW of red light. In 1.00 hr, the laser emits 2.29 * 1020 photons. What is the wavelength of the laser?2381views1rank
Textbook QuestionA particular laser consumes 150.0 watts of electrical power and produces a stream of 1.33 * 1019 1064-nm photons per second. What is the percent efficiency of the laser in converting electrical power to light?1780views
Textbook QuestionConsider the electronic structure of the element bismuth. (a) The first ionization energy of bismuth is Ei1 = +703 kJ/ mol. What is the longest possible wavelength of light that could ionize an atom of bismuth?1040views
Textbook QuestionA photovoltaic cell contains a p–n junction that that converts solar light to electricity. An optimum semiconductor would have its band-gap energy matched to the wavelength of maximum solar intensity at the Earth's surface. (b) Which of the following semiconductors absorb at a wavelength matched with maximum solar intensity? CdTe with a band-gap energy of 145 kJ/mol or ZnSe with a band-gap energy of 248 kJ/mol.323views
Textbook QuestionIron is commonly found as Fe, Fe2+, and Fe3+. (c) The third ionization energy of Fe is Ei3 = +2952 kJ/mol. What is the longest wavelength of light that could ionize Fe2+1g2 to Fe3+1g2?1642views
Textbook QuestionOne watt (W) is equal to 1 J/s. Assuming that 5.0% of the energy output of a 75 W light bulb is visible light and that the average wavelength of the light is 550 nm, how many photons are emitted by the light bulb each second?907views1rank
Textbook QuestionMicrowave ovens work by irradiating food with microwave radiation, which is absorbed and converted into heat. Assum-ing that radiation with l = 15.0 cm is used, that all the energy is converted to heat, and that 4.184 J is needed to raise the temperature of 1.00 g of water by 1.00 °C, how many photons are necessary to raise the temperature of a 350 mL cup of water from 20 °C to 95 °C?739views
Textbook QuestionRed light with a wavelength of 660 nm from a 3.0 mW diode laser shines on a solar cell. (b) How much current (in amperes) flows in the circuit of the solar cell if all the photons are absorbed by the cell and each photon produces one electron?548views
Open QuestionWhat is the longest wavelength of radiation with enough energy to break carbon-carbon bonds?180views
Open QuestionHospital X-ray generators emit X-rays with wavelength of about 15.0 nanometers (nm), where 1nm = 10−9 m. What is the energy of a photon of the X-rays?229views
Open QuestionCalculate the energy of the violet light emitted by a hydrogen atom with a wavelength of 410.1 nm.214views
Open QuestionA bright violet line occurs at 435.8 nm in the emission spectrum of mercury vapor. what amount of energy, in joules, must be released by an electron in a mercury atom to produce a photon of this light?217views
Open QuestionHow much energy (in kJ) do 3.0 moles of photons, all with a wavelength of 655 nm, contain?218views
Open QuestionCalculate the energy of the orange light emitted, per photon, by a neon sign with a frequency of 4.89 × 1014 Hz.203views
Open QuestionCalculate the energy of the green light emitted, per photon, by a mercury lamp with a frequency of 5.49 × 1014 Hz.262views
Open QuestionCalculate the energy of a photon of electromagnetic radiation at each of the following frequencies.271views
Open QuestionWhat is the longest wavelength of radiation that possesses the necessary energy to break the bond?266views
Open QuestionCalculate the energy of a photon of electromagnetic radiation at each of the following wavelengths.415views