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Ch 37: Special Relativity

Chapter 36, Problem 39

A hydrogen atom is in a state with energy -1.51 eV. In the Bohr model, what is the angular momentum of the electron in the atom, with respect to an axis at the nucleus?

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Welcome back, everyone. We are making observations about the electron of a singly ionized helium ion. We are told that it is excited to a higher state by absorption of electromagnetic radiation. Now, the energy of our electron moving in the circular planar orbit is going to be negative 3.4 electron volts. And we are tasked with finding what is the electrons angular momentum? Well, we have a formula for this our formula states that our angular momentum is equal to the principle number times Plank's constant divided by two pi. But what is the number for our electron? Well, we are told that the energy of an electron at an excited state N for the singly ionized helium ion is going to be equal to negative 13.6 electron volts divided by our principle number squared times our nuclear charge squared where a single ionized helium ion, our nuclear charge is simply going to be two rearranging our equation. What we get is that our excited state or our principle number is going to be equal to the square root of negative 13.6 times Z squared all divided by E N. We have all of these values. So let's go ahead and calculate N here we have that N is equal to the square root of negative 13.6 times two squared divided by negative 3.4, which gives us a principle number of four. With that in mind, let me go ahead and change colors. Here. We can go ahead and calculate our angular momentum. We have that our angular momentum is equal to four times plank's constant, which is 6.63 times 10 to the negative 34th divided by two pi which when we plug into our calculator, we get 4.22 times 10 to the negative 34th kilograms meters squared divided by seconds corresponding to our final answer. Choice of e Thank you all so much for watching. I hope this video helped. We will see you all in the next one.
Related Practice
Textbook Question
A beam of alpha particles is incident on a target of lead. A particular alpha particle comes in 'head-on' to a particular lead nucleus and stops 6.50x10^-14 m away from the center of the nucleus. (This point is well outside the nucleus.) Assume that the lead nucleus, which has 82 protons, remains at rest. The mass of the alpha particle is 6.64x10^-27 kg. (a) Calculate the electrostatic potential energy at the instant that the alpha particle stops. Express your result in joules and in MeV. (b) What initial kinetic energy (in joules and in MeV) did the alpha particle have? (c) What was the initial speed of the alpha particle?
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Textbook Question
The energy-level scheme for the hypothetical oneelectron element Searsium is shown in Fig. E39.25

. The potential energy is taken to be zero for an electron at an infinite distance from the nucleus. (b) An 18-eV photon is absorbed by a Searsium atom in its ground level. As the atom returns to its ground level, what possible energies can the emitted photons have? Assume that there can be transitions between all pairs of levels.
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Textbook Question
In a set of experiments on a hypothetical oneelectron atom, you measure the wavelengths of the photons emitted from transitions ending in the ground level (n = 1), as shown in the energy-level diagram in Fig. E39.27

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Textbook Question
A triply ionized beryllium ion, Be3+ (a beryllium atom with three electrons removed), behaves very much like a hydrogen atom except that the nuclear charge is four times as great. (a) What is the ground-level energy of Be3+? How does this compare to the ground-level energy of the hydrogen atom?
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Textbook Question
A triply ionized beryllium ion, Be3+ (a beryllium atom with three electrons removed), behaves very much like a hydrogen atom except that the nuclear charge is four times as great. (c) For the hydrogen atom, the wavelength of the photon emitted in the n = 2 to n = 1 transition is 122 nm (see Example 39.6). What is the wavelength of the photon emitted when a Be3+ ion undergoes this transition?
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Textbook Question
Find the longest and shortest wavelengths in the Lyman and Paschen series for hydrogen. In what region of the electromagnetic spectrum does each series lie?
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