What physical meaning is attributed to $\psi^2$, the square of the wave function?

How fast must a $56.5-\mathrm{g}$ tennis ball travel in order to have a de Broglie wavelength that is equal to that of a photon of green light $(5400 \text{\AA})$?

An alpha particle (mass $=6.6 \times 10^{-24} \mathrm{~g}$ ) emitted by radium travels at $3.4 \times 10^7 \pm 0.1 \times 10^7 \mathrm{mi} / \mathrm{h}$. What is its de Broglie wavelength (in meters)?

A 232-lb fullback runs the 40-yd dash at a speed of $19.8 \pm 0.1 \mathrm{mi} / \mathrm{h}$. What is his de Broglie wavelength (in meters)?

Why can't we overcome the uncertainty predicted by Heisenberg's principle by building more precise devices to reduce the error in measurements below the $h / 4 \pi$ limit?

In the mid- $17^{\text {th }}$ century, Isaac Newton proposed that light existed as a stream of particles, and the wave-particle debate continued for over 250 years until Planck and Einstein presented their revolutionary ideas. Give two pieces of evidence for the wave model and two for the particle model.

Consider the following types of electromagnetic radiation:
(1) microwave
(2) ultraviolet
(3) radio waves (4) infrared
(5) x-ray
(6) visible
(c) Arrange them in order of increasing energy.

Consider the following types of electromagnetic radiation:
(1) microwave
(2) ultraviolet
(3) radio waves (4) infrared
(5) x-ray
(6) visible
(b) Arrange them in order of increasing frequency.

Consider the following types of electromagnetic radiation:
(1) microwave
(2) ultraviolet
(3) radio waves (4) infrared
(5) x-ray
(6) visible
(a) Arrange them in order of increasing wavelength.

If particles have wavelike motion, why don't we observe that motion in the macroscopic world?

A Bohr-model representation of the $\mathrm{H}$ atom is shown below with several electron transitions depicted by arrows:
(b) Rank the emissions in terms of increasing energy.

A Bohr-model representation of the $\mathrm{H}$ atom is shown below with several electron transitions depicted by arrows:
a) Which transitions are absorptions and which are emissions?

In addition to continuous radiation, fluorescent lamps emit sharp lines in the visible region from a mercury discharge within the tube. Much of this light has a wavelength of $436 \mathrm{~nm}$. What is the energy (in J) of one photon of this light?

An electron in the $n=5$ level of an $\mathrm{H}$ atom emits a photon of wavelength $1281 \mathrm{~nm}$. To what energy level does the electron move?