Q: What is the value of Planck’s constant?

$$6.63 \times 10$$^{-34}$$ joules·sec

Question 1

Which experiment provided evidence that light behaves as both a wave and a particle?

Accepted Answer

The double-slit experiment

Question 2

According to the photoelectric effect, what determines whether electrons are ejected from a metal plate when light shines on it?

Accepted Answer

The frequency of the light

Question 3

What is the equation for the energy of a photon?

Accepted Answer

$$E = h \cdot f$$

Question 4

If the frequency of light is below a certain threshold, what happens in the photoelectric effect?

Accepted Answer

No electrons are ejected

Question 5

Which scientist first proposed that radiant energy is emitted in discrete bundles called quanta?

Accepted Answer

Max Planck

Question 6

What is the value of Planck’s constant?

Accepted Answer

$$6.63 	imes 10$$^{-34}$$ joules·sec

Question 7

Which statement best describes wave–particle duality?

Accepted Answer

Light exhibits both wave and particle properties depending on the situation

Question 8

In the double-slit experiment, what pattern emerges when monochromatic light passes through two slits?

Accepted Answer

An interference pattern of bright and dark fringes

Question 9

What happens when only one slit is open in the double-slit experiment?

Accepted Answer

A single-slit diffraction pattern forms

Question 10

What is the relationship between the energy of a photon and the frequency of light?

Accepted Answer

Energy is directly proportional to frequency

Question 11

What is the equation for the de Broglie wavelength of a particle?

Accepted Answer

$$\lambda = \frac{h}{p}$$

Question 12

Which principle states that the product of uncertainties in momentum and position must be greater than or equal to Planck’s constant divided by $$2\pi$$?

Accepted Answer

Heisenberg uncertainty principle

Question 13

What is the mathematical expression for the Heisenberg uncertainty principle?

Accepted Answer

$$\Delta p \Delta x \geq \hbar$$

Question 14

Which of the following best describes the emission spectrum of hydrogen?

Accepted Answer

It consists of discrete spectral lines that get closer together at higher energies

Question 15

What is observed in the absorption spectrum of a gas?

Accepted Answer

Dark lines at specific frequencies

Question 16

When an atom is excited, what happens to its electrons?

Accepted Answer

Electrons move to higher energy levels

Question 17

Which equation relates the energy difference between quantum states to the frequency of emitted light?

Accepted Answer

$$E = h \cdot f$$

Question 18

Which scientist showed that matter, like light, exhibits both wave and particle properties?

Accepted Answer

Louis de Broglie

Question 19

What is the consequence of the uncertainty principle for measurements in the macroscopic world?

Accepted Answer

It is negligible and does not affect typical laboratory measurements

Question 20

Which equation expresses the uncertainty principle for energy and time?

Accepted Answer

$$\Delta E \Delta t \geq h$$

Light Quanta, Wave-Particle Duality, and Quantum Physics: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards