Slide 1 / 72 Slide 2 / 72 Chemistry Atomic Structures Practice Problems 2015-10-27 www.njctl.org 1 According to Einstein s view of matter and energy, what is the common link between light and matter? Slide 3 / 72
2 What is Chemistry? Slide 4 / 72 3 How does diffraction effect the double slit experiment? Slide 5 / 72 4 The wavelength of light emitted from a traffic light having a frequency of 6.15x10 14 Hz is. Slide 6 / 72
5 An electromagnetic wave has a frequency of 6x 10 5 Hz. What is the wavelength? Slide 7 / 72 6 An electromagnetic wave has a wavelength of 5x 10-13 m. What is the frequency? Slide 8 / 72 7 An electromagnetic wave has a frequency of 9x10-7 Hz. What is the wavelength? Slide 9 / 72
8 What is the frequency of yellow sodium light that has a wavelength of 579nm? Slide 10 / 72 9 Electromagnetic radiation with a wavelength of nm appears as green light to the human eye. The frequency of this light is 5.71x10 14 Hz. Slide 11 / 72 10 Explain Newton s original ideas about the nature of light. Slide 12 / 72
11 While standing in a room with two speakers (speakers A and B), each emitting sound with a wavelength of 2m, you notice you cannot hear the sound. Compared to the closer speaker, what s the smallest difference in distance to the further speaker (ignore reflection of sound off of walls etc). Slide 13 / 72 12 While standing in a room with two speakers (speakers A and B) centered about the center of the room, pointed at the wall. You notice you cannot hear the sound while standing 1 meter from the center of the far wall. What s the next distance from the center you could stand at that would you to hear the sound at its loudest? Slide 14 / 72 13 How are matter and energy related? Slide 15 / 72
14 Why is the understanding of energy and matter vital to one s understanding of Chemistry? Slide 16 / 72 15 How does interference effect the double slit experiment? Slide 17 / 72 16 A radio station broadcasts at 101.5 MHz. The wavelength of the signal is m. Slide 18 / 72
17 An electromagnetic wave has a wavelength of 1.5 nm. What is the frequency? Slide 19 / 72 18 An electromagnetic wave has a wavelength of 5x10-13 m. What is the frequency? Slide 20 / 72 19 An electromagnetic wave has a wavelength of 300 m. What is the frequency? Slide 21 / 72
20 What is the frequency of orange lithium light that has a wavelength of 650nm? Slide 22 / 72 21 An FM radio station broadcasts electromagnetic radiation at a frequency of 99.5 MHz. The wavelength of this radiation is m. Slide 23 / 72 22 What is the frequency, in Hz, of electromagnetic radiation that has a wavelength of 0.55 m? Slide 24 / 72
23 What is the frequency of light, in Hz, that has a wavelength of 1.23x10-6 cm? Slide 25 / 72 24 What is the wavelength of light (nm) that has a frequency of 3.22x10 14 Hz? Slide 26 / 72 25 What is the wavelength of light (nm) that has a frequency 4.25x10 14 Hz? Slide 27 / 72
26 Explains Hyugen s original ideas about the nature of light. Slide 28 / 72 27 How are the properties of fluids in a tank, sound from a set of speakers, and light passing through a double slit all related to one another? Slide 29 / 72 28 While standing in a room with two speakers (speakers A and B) centered about the center of the room, pointed at the wall. You notice you cannot hear the sound while standing 1 meter from the center of the far wall. What s the next distance from the center you could stand at that would still prevent you from hearing the sound. Slide 30 / 72
29 What is the energy of a photon that has a frequency of 7.0 x 10 15 Hz? Slide 31 / 72 30 What is the energy of a photon that has a frequency of 4.5 x 10 15 Hz? Slide 32 / 72 31 What is the energy of a photon that has a wavelength of 720 nm? Slide 33 / 72
32 Electromagnetic radiation with a wavelength of 531 nm appears as green light to the human eye. The energy of one photon of this light is 3.74 x10-19 J. Thus, a laser that emits 2.3 x10-2 J of energy in a pulse of light at this wavelength produces photons in each pulse. Slide 34 / 72 33 The wavelength of a photon that has energy of 5.65 x 10-19 J is nm. Slide 35 / 72 34 What is the frequency (Hz) of a photon that has energy of 4.38 x 10-18 J? Slide 36 / 72
35 The energy of a photon that has a frequency of 7.75 x 10 14 Hz is J. Slide 37 / 72 36 What is the energy of a photon that has a wavelength of 450 nm? Slide 38 / 72 37 Electromagnetic radiation with a wavelength of 525 nm appears as green light to the human eye. The energy of one photon of this light is J. Slide 39 / 72
38 The energy of a photon that has a wavelength of 10.0 m is J Slide 40 / 72 39 What implication does the equation ρ=h/λ have on how we view matter or anything with momentum. Slide 41 / 72 40 What is the wavelength of an electron which has a velocity of 3.5 x 10 7 m/s? (m e = 9.11x10-31 kg) Slide 42 / 72
41 The de Broglie wavelength of a 12.0 gram bullet traveling at the speed of sound is m. The speed of sound is 331 m/sec. Slide 43 / 72 42 The de Broglie wavelength of an electron with a velocity of 6.00 x10 6 m/s is m. (m e = 9.11x10-31 kg) Slide 44 / 72 43 What is the wavelength of an electron which has a velocity of 6.0 x 10 7 m/s? (me = 9.11x10-31 kg) Slide 45 / 72
44 Why would the dual nature of matter make it difficult to observe very small particles like electrons? Slide 46 / 72 45 What is the wavelength of an electron which has a velocity of 1.2 x 10 8 m/s? (me = 9.11x10-31 kg) Slide 47 / 72 46 The de Broglie wavelength of a 10.0 gram whip traveling at the speed of sound is m. The speed of sound is 331 m/sec. Slide 48 / 72
47 The de Broglie wavelength of an electron with a velocity of 1.30 x10 7 m/s is m. (m e = 9.11x10-31 kg) Slide 49 / 72 48 What is the wavelength of an electron which has a velocity of 4.0 x 10 7 m/s? (m e = 9.11x10-31 kg) Slide 50 / 72 49 Why do neutral atoms have the same numbers of protons and electrons? Slide 51 / 72
50 What about electrons allow them to be some of the fastest traveling sub atomic particles? Slide 52 / 72 51 Why was it important to use alpha particles in order to discover the neucleus, as opposed to gamma rays or beta particles? Slide 53 / 72 52 Based on Bohr s model of the atom, why do you think electrons were the first subatomic particle to be discovered? Slide 54 / 72
53 Based off of the first experiments into the composition of atoms, why were neutrons the last particles to be discovered? Slide 55 / 72 54 As more and more protons enter the nucleus of an atom, increasing ratios of neutrons are needed. Why do you think this is? Slide 56 / 72 55 Why is it not possible for an electron to continue in a set orbit around the nucleus like a planet around the sun? Slide 57 / 72
56 Explain how emission spectra of gasses helped scientists to determine electrons traveled in energy levels. Slide 58 / 72 57 Give one example of black body radiation that you see in your everyday life. Slide 59 / 72 58 The binding energy of the hydrogen atom in its ground state is -13.6 ev. What is the energy when it is in the n = 4 state? Slide 60 / 72
59 What is the energy of the second excited state (n=3) of hydrogen? Slide 61 / 72 60 What is the energy of the ground state (n=1) of hydrogen? Slide 62 / 72 61 How much energy does an electron in hydrogen need as it jumps from ground state to the second excited state? Slide 63 / 72
62 If an electron returns from the second excited state to ground state, what 3 Energies of photons could it emit? Slide 64 / 72 63 If an electron returns from the second excited state to ground state, what 3 frequencies of photons could it emit? Slide 65 / 72 64 A Hydrogen electron drops from its sixth excited state back down to its forth excited state. A B C D E F What are the n values associated with these two states? How many different types of photons can it emit? What is change in energy (in ev) associated with each transition? What is the frequency associated with each of the emitted electrons? What is the wavelength associated with each of the emitted electrons? What possible types of electromagnetic radiation are given off during this transition? Slide 66 / 72
65 The wavelength of a ruby laser is 694.3 nm. What is the energy difference (in ev) between the two energy states involved in laser action? Slide 67 / 72 66 In state n = 1, the energy of the hydrogen atom is - 13.58 ev. What is its energy in state n = 2? Slide 68 / 72 67 If an electron returns from the second excited state to ground state, what 3 wavelengths (in nm) of photons could it emit? Slide 69 / 72
68 If an electron returns from the second excited state to ground state, what 3 types of EM Radiation could it emit (if visible light is emitted, include the color)? Slide 70 / 72 69 The electron of a hydrogen atom makes a transition from the n = 5 state to the n = 2 state. What is the wavelength of the emitted photon? Slide 71 / 72 70 A Hydrogen electron drops from its forth excited state back down to its first excited state. A B C What are the n values associated with these two states? How many different types of photons can it emit? What is change in energy (in ev) associated with each transition? Slide 72 / 72 D E F What is the frequency associated with each of the emitted electrons? What is the wavelength associated with each of the emitted electrons? What possible types of electromagnetic radiation are given off during this transition?