Absorption and Emission of Atomic Spectra (TOPIC)

RECAP TRUE OR FALSE: Write the word TRUE if the statement is correct and FALSE if the statement is incorrect then change the underlined word/s to make the statement correct. 1. Reference frames that move with constant velocity are called inertial reference frames. 2. Special relativity was postulated by Albert Einstein. 3. The time interval between two events measured by a moving observer who views events as occurring in different places is longer than the time interval measured by the observer at rest who views events as happening in the same place. 4. Length contraction is another consequence of special relativity wherein the length of an object is measured by an observer in an inertial frame of reference that is moving with respect to the object is less than its proper length. 5. The mass of an object moving at a speed approaching that of the speed of light is greater than its mass is called rest mass.ACTIVITIES Problem solving: Solve the following problems. 1. ms Studies of the spectral lines of hydrogen show that the highest frequency of lct'llg radiation emitted by a hydrogen atom is about 3.23 x 1D'5Hs. a. What is the energy of one of the corresponding photons? b. Does this light fall in the infrared, visible, or ultraviolet part of the electromagiee spectrum? Hint: the approximate shortwavelength end of the visible range is at It - 40D nm. o. How does this photon energy oompane with the ionization energy of the hydrogen atom, 13.6 eV? A photon has an energy of e'f. What is the frequency of the radian'on? . How many photons of red light [l- nm] does it take to have a total energy of L]? VALUING Cite at least four practical applications of atomic spectra in our daily life. 1 2 Applications of absorption and emisssion of atomic spectra LUlChoose the letter of the correct answer. 1. What color is the light emitted by hydrogen when an electron makes the transition from energy; level 5 to energy level 2? C. Red E. Blue C. violet D. yellow 2. What is the emission of electrons when electromagnetic radiation falls on an object? it. Threshold frequency C. Compton Effect E. Heisenberg Principle D. photoelectric effect 3. I have a glass tube lled with hydrogen gas. I shine white light onto the tube. The spectrum I then measure has an absorption line at a wavelength of 4?4 mn. Between which two energy.F levels did the transition occur? The variable 11 can have an],r real number value. A. From energy level 4 to energy level 2 B. From energy level 3 to energy level 2 C. From energy 2 to energy level 4 D. From energy level 5 to energy level 2 4. Which of the following equations expresses the wavelength of a particle in terms of its momentum? A hf B. Ap C. D. mv 5. A laser gives a monochromatic ultraviolet light with a wavelength of 344 nm. What is the energy of each photon of light? C. 1.93 x 10-27eV C. 1.93 x 10-27J D. 5.78 x 10-19 eV D. 5.78 x 10-19J