IB Physics HL: Quantum and Nuclear Physics Mastery Quiz

1. Describe the photoelectric effect.

The photoelectric effect occurs at any frequency of light, but the intensity determines the number of electrons emitted.

The photoelectric effect involves the emission of protons from a metal surface when exposed to light.

The photoelectric effect is a result of chemical reactions between light and the metal surface.

The photoelectric effect involves the emission of electrons, not protons. It occurs only above the threshold frequency, and the number of electrons emitted depends on intensity, not frequency. The process is not due to chemical reactions.

Explanation

The photoelectric effect involves the emission of electrons, not protons. It occurs only above the threshold frequency, and the number of electrons emitted depends on intensity, not frequency. The process is not due to chemical reactions.

2. Explain how atomic spectra provide evidence for the quantization of energy in atoms.

B. The energy levels of electrons in atoms have no direct relation to the observed spectral lines.

C. Electrons in atoms can move between energy levels in a continuous manner without emitting light.

A. Atomic spectra show continuous changes in energy levels in atoms.

D. The concept of quantized energy states in atoms does not play a significant role in understanding atomic spectra.

The correct answer explains how energy differences between allowed electron energy states support the quantization of energy in atoms, while the incorrect answers provide misleading statements that do not accurately reflect the evidence provided by atomic spectra.

Explanation

The correct answer explains how energy differences between allowed electron energy states support the quantization of energy in atoms, while the incorrect answers provide misleading statements that do not accurately reflect the evidence provided by atomic spectra.

3. Explain how the radii of nuclei may be estimated from charged particle scattering experiments.

Estimates can't be made from charged particle scattering experiments.

There is no relation between charged particle scattering experiments and estimating radii of nuclei.

Radii can be estimated only using theoretical calculations, not experiments.

4. Describe how the masses of nuclei may be determined using a Bainbridge mass spectrometer.

Nuclear masses are determined by analyzing the number of electrons surrounding the nucleus.

Masses of nuclei are determined by heating them until they vaporize, then condensing the vapor and weighing the resulting solid.

The correct method for determining the masses of nuclei using a Bainbridge mass spectrometer involves passing positive ions of elements through electric and magnetic fields, and then detecting the particles to determine mass values. It does not involve methods like heating and condensing the nuclei, analyzing the number of electrons, or measuring volume to calculate density.

Explanation

The correct method for determining the masses of nuclei using a Bainbridge mass spectrometer involves passing positive ions of elements through electric and magnetic fields, and then detecting the particles to determine mass values. It does not involve methods like heating and condensing the nuclei, analyzing the number of electrons, or measuring volume to calculate density.

5. Describe one piece of evidence for the existence of nuclear energy levels.

Alpha particles and gamma rays have the same energy levels in all nuclei.

Nuclear energy levels can be continuously varied, with no specific values.

Nuclear energy levels are not related to the decay of a nucleus but rather to external factors.

The correct answer highlights that alpha particles and gamma rays have discrete energies when emitted by a nucleus, indicating the existence of nuclear energy levels.

Explanation

The correct answer highlights that alpha particles and gamma rays have discrete energies when emitted by a nucleus, indicating the existence of nuclear energy levels.

6. Describe ?+ decay, including the existence of the neutrino.

Beta-plus decay involves the emission of a positron and a neutrino from the nucleus.

Students should know that ? energy spectra arecontinuous, and that the neutrino was postulatedto account for these spectra.

Alpha decay involves the emission of a helium nucleus from a heavy nucleus.

Gamma decay involves the emission of high-energy photons from an excited nucleus.

In this question, we are discussing ?+ decay and specifically the existence of neutrino to account for continuous energy spectra. The incorrect answers provided refer to different types of nuclear decay processes to create options for a multiple-choice question.

Explanation

In this question, we are discussing ?+ decay and specifically the existence of neutrino to account for continuous energy spectra. The incorrect answers provided refer to different types of nuclear decay processes to create options for a multiple-choice question.

7. State the radioactive decay law as an exponential function and define the decay constant.

The exponential function in the decay law is N = Noe^(-kt).

The decay constant is the total number of radioactive nuclei in a sample.

The decay constant is the number of nuclei that decay per unit time.

The correct answer explains that the decay constant is the probability of decay of a nucleus per unit time and provides the correct formula for the radioactive decay law. The incorrect answers suggest misconceptions related to decay constant and the exponential function in the decay law.

Explanation

The correct answer explains that the decay constant is the probability of decay of a nucleus per unit time and provides the correct formula for the radioactive decay law. The incorrect answers suggest misconceptions related to decay constant and the exponential function in the decay law.