Activity 1:The birth of quantum theory Name: Name: Identity document Identity document 1. Answer the following questions: a) What is the coulombian force? b) What is the definition of the electric field? c) What characterizes the space surrounding an electrical charge? d ) What is the definition of potential energy? e) What is the expression of the potential energy associated with the interaction of two charged particles? 11. The maximum emission wavelength of a blackbody is found by deriving and equating the Planck equation to zero. This result is known as Wien’s law of displacement, k λmax = T k = 0,0028976Km. ¿what temperature is a blackbody that has a maximum emission in a) 100 nm b) 25 nm c) 2.5 nm d) 0.12 nm ? f ) What is the electric potential? 12. One surface temperature is 5000K.How much power is radiated by the surface? g) What is the equation that describes the magnetic force experienced by a charged particle? 13. What is the consistency of the photoelectric effect experiment? h) What is the equation that describes the magnetic force experienced by a charged particle? 2. Describe in detail the discovery of the electron 3. Describe in detail the experiment to determine the charge of the electron? 4. What an electromagnetic wave?. Describe all the intervals of the wavelengths and frequency 5. Draw a sine wave. a) Indicate what the wavelength corresponds to in that drawing. b) If this wave propagates in time, as a when half of its period has elapsed? What will it be like when your period has elapsed? 6. What is the relationship between the period and the frequency of a wave? 7. What is the relationship between the frequency and the wavelength of a wave? 8. Complete the next table ν(Hz) λ(m) 15. when lithium is irradiated with light 300nm the cinetic energy of the electron is 2,935 × 10−19 J, whereas when irradiated with light from 400nm is 1,280 × 10−19 J. From these data calculate the Planck constant, the threshold frequency and the working function of lithium 16. Indicate the units of the next magnitude a) b) c) d) e) f) g) h) Force Energy Charge Fild electric Coulomb constant Fild magnetic Wavelength wave number i ) Period j ) Frequency k ) The potential electrostatic l ) Boltzmann constant m) Planck constant n) Cinetic energy 17. Draw a picture of the absorption and emission spectra of a gas. Compare them ν̃(m−1 ) E (J) 1,2 × 10−19 2,8 × 10−10 18. Deduce the Rydberg equation from the Balmer equation. 19. Using the Rydberg formula calculate the wavelength of the first 10 lines that belong to the Lyman series(n2 = 1). What is observed when the n1 number increases? 2,8 × 1010 6,7 × 10 14. ¿what corresponds the braking potential in an experiment to study the photoelectric effect? 12 3,3 7,8 × 1015 9. What is the transfer of energy through radiation? 10. Make a schematic drawing of the blackbody emission spectrum at two different temperatures.. 20. Using the Rydberg formula calculate the wavelength of the first line of the hydrogen atom series with n2 = 1, 2, 3, 4, 5, 6, 7, 8, 9. ¿What is observed when the n2 number increases? 21. Using treatment, determine the energy of a system 22. Taking into account Bohr’s atomic model, determine the energy of a system as a function of n and Z 23. Calculate the radius of the first four Bohr orbits for the hydrogen atom (Z = 1, n = 1, 2, 3, 4) 24. Calculate the wavenumber of the photon required in the transition from the first to the sixth Bohr orbit of hydrogen. 25. Compare the value of the Rydberg constant obtained from the Balmer equation and that obtained by the Bohr model for the hydrogen atom 26. What is the wavelength, in nanometers, associated with a 1000 kg automobile traveling at a speed of 25 ms−1 , that is, considering the automobile to be amatter wave? Comment on the feasibility of an experimental measurement of this wavelength. 27. Infrared lamps are used in cafeterias to keep food warm. How many photons per second are produced by an in- frared lamp that consumes energy at the rate of 95 W and is 14 % efficient in converting this energy to infrared radiation? Assume that the radiation has a wavelength of 1525 nm. 28. By using a two-photon process (that is, two sequential excitations), a chemist is able to excite the electron in a hydrogen atom to the 5d level. Not all excitations are possible; they are governed by a selection rule. The selection rule states that the allowed excitations must have ∆l = +1 or −1 and ∆n can have any value. Use this selection rule to identify the possible intermediate levels (more than one are possible) involved, and calculate the frequencies of the two photons involved in each process. Identify the transitions allowed when a sample of hydrogen atoms excited to the 5d level exhibits an emission spectrum. When a sample of gaseous sodium atoms is similarly excited to the 5d level, what would be the difference in the emission spectrum observed?
