All Matches

Solution Library

Expert Answer

Textbooks

Search Textbook questions, tutors and Books

Oops, something went wrong!

Change your search query and then try again

Result Not Found

Books FREE
Tutors
Study Help
Ask a Question

Search
Sign In
Register

study help
physics
university physics

Questions and Answers of University Physics

An atom in its ground level absorbs a photon with energy equal to the K absorption edge. Does absorbing this photon ionize this atom? Explain.
The nucleus of a gold atom contains 79 protons. How does the energy required to remove a 1s electron completely from a gold atom compare with the energy required to remove the electron from the
What is the “central-field approximation” and why is it only an approximation?
The ionization energies of the alkali metals (that is, the lowest energy required to remove one outer electron when the atom is in its ground state) are about 4 or 5 eV, while those of the noble
A small amount of magnetic-field splitting of spectral lines occurs even when the atoms are not in a magnetic field. What causes this?
On the basis of the Pauli exclusion principle, the structure of the periodic table of the elements shows that there must be a fourth quantum number in addition to n, l, and ml . Explain.
Use Table 41.3 to help determine the ground-state electron configuration of the neutral gallium atom (Ga) as well as the ions Ga+ and Ga-. Gallium has an atomic number of 31. Table 41.3
Why do the transition elements 1Z = 21 to 302 all have similar chemical properties?
The central-field approximation is more accurate for alkali metals than for transition metals such as iron, nickel, or copper. Why?
In the ground state of the helium atom one electron must have “spin down” and the other “spin up.” Why?
In the Stern–Gerlach experiment, why is it essential for the magnetic field to be inhomogeneous (that is, nonuniform)?
What is the energy difference between the two lowest energy levels for a proton in a cubical box with side length 1.00 × 10-14 m, the approximate diameter of a nucleus?
The Stern–Gerlach experiment is always performed with beams of neutral atoms. Wouldn’t it be easier to form beams using ionized atoms? Why won’t this work?
Why is the analysis of the helium atom much more complex than that of the hydrogen atom, either in a Bohr type of model or using the Schrödinger equation?
A photon is emitted when an electron in a three dimensional cubical box of side length 8.00 × 10-11 m makes a transition from the nX = 2, nY = 2, nZ = 1 state to the nX = 1, nY = 1, nZ = 1 state.
Dots that are the same size but made from different materials are compared. In the same transition, a dot of material 1 emits a photon of longer wavelength than the dot of material 2 does. Based on
According to this model, which statement is true about the energy-level spacing of dots of different sizes?(a) Smaller dots have equally spaced levels, but larger dots have energy levels that get
A harmonic oscillator absorbs a photon of wavelength 6.35 mm when it undergoes a transition from the ground state to the first excited state. What is the groundstate energy, in electron volts, of the
Sketch the wave function for the potential-energy well shown in Fig. Q40.26 when E1is less than U0and when E3is greater than U0.Figure Q40.26 UCx) 00 00 Uo х
Compare the allowed energy levels for the hydrogen atom, the particle in a box, and the harmonic oscillator. What are the values of the quantum number n for the ground level and the second excited
In Fig. 40.28, how does the probability of finding a particle in the center half of the region -A < x < A compare to the probability of finding the particle in the outer half of the region? Is
The probability distributions for the harmonic-oscillator wave functions (see Figs. 40.27 and 40.28) begin to resemble the classical (Newtonian) probability distribution when the quantum number n
The wave function shown in Fig. 40.20 is nonzero for both x < 0 and x > L. Does this mean that the particle splits into two parts when it strikes the barrier, with one part tunneling through
Qualitatively, how would you expect the probability for a particle to tunnel through a potential barrier to depend on the height of the barrier? Explain.
In classical (Newtonian) mechanics, the total energy E of a particle can never be less than the potential energy U because the kinetic energy K cannot be negative. Yet in barrier tunneling a particle
Figure 40.17 shows the scanning tunneling microscope image of 48 iron atoms placed on a copper surface, the pattern indicating the density of electrons on the copper surface. What can you infer about
It is stated in Section 40.3 that a finite potential well always has at least one bound level, no matter how shallow the well. Does this mean that as U0 → 0, E1 → 0? Does this violate the
Figure 40.15a shows that the higher the energy of a bound state for a finite potential well, the more the wave function extends outside the well (into the intervals x < 0 and x > L). Explain
A particle is confined to a finite potential well in the region 0 < x < L. How does the area under the graph of |ψ|2 in the region 0 < x < L compare to the total area under the graph of
An electron in a one dimensional box has ground state energy 2.00 eV. What is the wavelength of the photon absorbed when the electron makes a transition to the second excited state?
In Fig. 40.12b, the probability function is zero at the points x = 0 and x = L, the €œwalls€ of the box. Does this mean that the particle never strikes the walls?
For a particle in a finite potential well, is it correct to say that each bound state of definite energy is also a state of definite wavelength? Is it a state of definite momentum? Explain.
For a particle confined to an infinite square well, is it correct to say that each state of definite energy is also a state of definite wavelength? Is it also a state of definite momentum? Explain.
A particle in a box is in the ground level. What is the probability of finding the particle in the right half of the box? (Refer to Fig. 40.12, but don€™t evaluate an integral.) Is the
In Chapter 15 we represented a standing wave as a superposition of two waves traveling in opposite directions. Can the wave functions for a particle in a box also be thought of as a combination of
For a particle in a box, what would the probability distribution function |ψ|2 look like if the particle behaved like a classical (Newtonian) particle? Do the actual probability distributions
Let Î¨1and Î¨2be two solutions of Eq. (40.23) with energies E1and E2, respectively, where E1‰ E2. Is Î¨ = AÎ¨1+ BÎ¨2, where A and B are
If ψ is normalized, what is the physical significance of the area under a graph of |ψ|2 versus x between x1 and x2? What is the total area under the graph of |ψ|2 when all x are included? Explain.
Laser light results from transitions from long-lived metastable states. Why is it more monochromatic than ordinary light?
Which has more total energy: a hydrogen atom with an electron in a high shell (large n) or in a low shell (small n)? Which is moving faster: the high shell electron or the low-shell electron? Is
You have been asked to design a magnet system to steer a beam of 54 eV electrons like those described in Example 39.. The goal is to be able to direct the electron beam to a specific target location
Galaxies tend to be strong emitters of Lyman-α photons (from the n = 2 to n = 1 transition in atomic hydrogen). But the intergalactic medium the very thin gas between the galaxies— tends to absorb
When an electron beam goes through a very small hole, it produces a diffraction pattern on a screen, just like that of light. Does this mean that an electron spreads out as it goes through the hole?
In our universe, the rest energy of an electron is approximately 8.2 × 10-14 J. What would it be in the alternate universe?(a) 8.2 × 10-8 J;(b) 8.2 × 10-26 J;(c) 8.2 × 10-2 J;(d) 0.82 J.Our
For the particle in a box, we chose k = np/L with n = 1, 2, 3, c to fit the boundary condition that ψ = 0 at x = L. However, n = 0, -1, -2, -3, c also satisfy that boundary condition. Why didn’t
If a particle is in a stationary state, does that mean that the particle is not moving? If a particle moves in empty space with constant momentum p̅(vector) and hence constant energy E = p2/2m, is
Why must the wave function of a particle be normalized?
As Eq. (40.21) indicates, the time-dependent wave function for a stationary state is a complex number having a real part and an imaginary part. How can this function have any physical meaning, since
A student remarks that the relationship of ray optics to the more general wave picture is analogous to the relationship of Newtonian mechanics, with well-defined particle trajectories, to quantum
An electron is moving as a free particle in the -x-direction with momentum that has magnitude 4.50 × 10-24 kg ∙ m/s. What is the one dimensional time dependent wave function of the electron?
If quantum mechanics replaces the language of Newtonian mechanics, why don’t we have to use wave functions to describe the motion of macroscopic bodies such as baseballs and cars?
In the second type of helium-ion microscope, a 1.2-MeV ion passing through a cell loses 0.2 MeV per mm of cell thickness. If the energy of the ion can be measured to 6 keV, what is the smallest
Why is it easier to use helium ions rather than neutral helium atoms in such a microscope?(a) Helium atoms are not electrically charged, and only electrically charged particles have wave
Can the first type of helium-ion microscope, used for surface imaging, produce helium ions with a wavelength of 0.1 pm?(a) Yes; the voltage required is 21 kV.(b) Yes; the voltage required is 42
How does the wavelength of a helium ion compare to that of an electron accelerated through the same potential difference?(a) The helium ion has a longer wavelength, because it has greater mass.(b)
To investigate the structure of extremely small objects, such as viruses, the wavelength of the probing wave should be about one-tenth the size of the object for sharp images. But as the wavelength
The wavelength 10.0 µm is in the infrared region of the electromagnetic spectrum, whereas 600 nm is in the visible region and 100 nm is in the ultraviolet. What is the temperature of an ideal
Using a mixture of CO2, N2, and sometimes He, CO2 lasers emit a wavelength of 10.6 µm. At power outputs of 0.100 kW, such lasers are used for surgery. How many photons per second does a CO2 laser
(a) For one-electron ions with nuclear charge Z, what is the speed of the electron in a Bohr-model orbit labeled with n? Give your answer in terms of v1, the orbital speed for the n = 1 Bohr orbit in
The energy-level scheme for the hypothetical one electron 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
When you check the air pressure in a tire, a little air always escapes; the process of making the measurement changes the quantity being measured. Think of other examples of measurements that change
Why can an electron microscope have greater magnification than an ordinary microscope?
As the lower half of Fig. 39.4 shows, the diffraction pattern made by electrons that pass through aluminum foil is a series of concentric rings. But if the aluminum foil is replaced by a single
Could an electron-diffraction experiment be carried out using three or four slits? Using a grating with many slits? What sort of results would you expect with a grating? Would the uncertainty
Equation (39.30) states that the energy of a system can have uncertainty. Does this mean that the principle of conservation of energy is no longer valid? Explain.Eq.39.30Δt ΔE ≥ h/2
Suppose a two-slit interference experiment is carried out using an electron beam. Would the same interference pattern result if one slit at a time is uncovered instead of both at once? If not, why
Does the uncertainty principle have anything to do with marksmanship? That is, is the accuracy with which a bullet can be aimed at a target limited by the uncertainty principle? Explain.
Why go through the expense of building an electron microscope for studying very small objects such as organic molecules? Why not just use extremely short electromagnetic waves, which are much cheaper
Do the planets of the solar system obey a distance law (rn = n2r1) as the electrons of the Bohr atom do? Should they? Why (or why not)?
Higher-energy photons might be desirable for the treatment of certain tumors. Which of these actions would generate higher-energy photons in this linear accelerator?(a) Increasing the number of
If a proton and an electron have the same kinetic energy, which has the longer de Broglie wavelength? Explain.
Does a photon have a de Broglie wavelength? If so, how is it related to the wavelength of the associated electromagnetic wave? Explain.
A doubly ionized lithium atom (Li++) is one that has had two of its three electrons removed. The energy levels of the remaining single-electron ion are closely related to those of the hydrogen atom.
The emission of a photon by an isolated atom is a recoil process in which momentum is conserved. Thus Eq. (39.5) should include a recoil kinetic energy Kr for the atom. Why is this energy negligible
How might the energy levels of an atom be measured directly that is, without recourse to analysis of spectra?
Elements in the gaseous state emit line spectra with well defined wavelengths. But hot solid bodies always emit a continuous spectrum that is, a continuous smear of wavelengths. Can you account for
As a body is heated to a very high temperature and becomes self luminous, the apparent color of the emitted radiation shifts from red to yellow and finally to blue as the temperature increases. Why
The speed of light relative to still water is 2.25 × 108 m/s. If the water is moving past us, the speed of light we measure depends on the speed of the water. Do these facts violate Einstein’s
If the airplane of Passage Problem 37.71 has a rest mass of 20,000 kg, what is its relativistic mass when the plane is moving at 180 m/s ?(a) 8000 kg;(b) 12,000 kg;(c) 16,000 kg;(d) 25,000 kg;(e)
According to the photon model, light carries its energy in packets called quanta or photons. Why then don’t we see a series of flashes when we look at things?
Why must engineers and scientists shield against x-ray production in high-voltage equipment?
In attempting to reconcile the wave and particle models of light, some people have suggested that the photon rides up and down on the crests and troughs of the electromagnetic wave. What things are
Some lasers emit light in pulses that are only 10-12 s in duration. The length of such a pulse is (3 × 108 m/s)(10-12 s) = 3 × 10-4 m = 0.3 mm. Can pulsed laser light be as monochromatic as light
X rays with an initial wavelength of 0.900 × 10-10 m undergo Compton scattering. For what scattering angle is the wavelength of the scattered x rays greater by 1.0% than that of the incident x rays?
(a) If only a fraction p of the electric power supplied is converted into x rays, at what rate is energy being delivered to the target?(b) If the target has mass m and specific heat c (in J/kg ∙
How much energy is imparted to one cell during one day’s treatment? Assume that the specific gravity of the tumor is 1 and that 1 J = 6 × 1018 eV.(a) 120 keV;(b) 12 MeV;(c) 120 MeV;(d) 120 × 103
While interacting with molecules (mainly water) in the tumor tissue, each Compton electron or photoelectron causes a series of ionizations, each of which takes about 40 eV. Estimate the maximum
The probability of a photon interacting with tissue via the photoelectric effect or the Compton effect depends on the photon energy. Use Fig. P38.44 to determine the best description of how the
Can Compton scattering occur with protons as well as electrons? For example, suppose a beam of x rays is directed at a target of liquid hydrogen. (Recall that the nucleus of hydrogen consists of a
A photon of frequency f undergoes Compton scattering from an electron at rest and scatters through an angle ϕ. The frequency of the scattered photon is f'. How is f' related to f? Does your answer
In a photoelectric-effect experiment, which of the following will increase the maximum kinetic energy of the photoelectrons?(a) Use light of greater intensity;(b) Use light of higher frequency;(c)
In an experiment involving the photoelectric effect, if the intensity of the incident light (having frequency higher than the threshold frequency) is reduced by a factor of 10 without changing
In a photoelectric-effect experiment, the photocurrent i for large positive values of VAC has the same value no matter what the light frequency f (provided that f is higher than the threshold
Explain why Fig. 38.4 shows that most photoelectrons have kinetic energies less than hf - f, and also explain how these smaller kinetic energies occur.Fig.38.4 The stopping potential Vo is
Human skin is relatively insensitive to visible light, but ultraviolet radiation can cause severe burns. Does this have anything to do with photon energies? Explain.
Most black-and-white photographic film (with the exception of some special-purpose films) is less sensitive to red light than blue light and has almost no sensitivity to infrared. How can these
During the photoelectric effect, light knocks electrons out of metals. So why don’t the metals in your home lose their electrons when you turn on the lights?
Would you expect effects due to the photon nature of light to be generally more important at the low-frequency end of the electromagnetic spectrum (radio waves) or at the high-frequency end (x rays
There is a certain probability that a single electron may simultaneously absorb two identical photons from a high-intensity laser. How would such an occurrence affect the threshold frequency and the
In what ways do photons resemble other particles such as electrons? In what ways do they differ? Do photons have mass? Do they have electric charge? Can they be accelerated? What mechanical

Showing 200 - 300 of 1969

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Last

Get In Touch

About Us
Contact Us
Career
Jobs
FAQ
Campus Ambassador

Company Info

Security
Copyrights
Privacy Policy
Terms & Condition
SolutionInn Fee
Scholarship

Services

Sitemap
Fun
Definitions
Become Tutor
Study Help Categories
Recent Questions
Expert Questions

Copyright © 2024 SolutionInn All Rights Reserved.

Get the SolutionInn - Study Help App