Dual Nature of light Warm-Up, Instruction, Assignment, and Quiz

Which describes the results of the double slit experiment? Check all that apply. Waves produced a diffraction pattern. Results supported the wave theory of light. Results demonstrated the relationship between electric and magnetic fields. Beams of light separated as they passed through a prism. Results supported the particle theory of light.

1, & 2

Which ideas held by the ancient Greeks have been at least partially supported by scientific experiments, calculations, and observations made throughout history? Check all that apply. Light is a wave or disturbance that travels through spaces in the air. Light is a substance carrying particles that flow from a light source. Light is a stream of rays that comes with great velocity from the eyes of an observer. Light is the result of rays that leave the eyes, reflect off an object, and interact with sunlight to become visible. Light is made of a combination of electric and magnetic fields that travel at the speed of light.

1, & 2

Identifying Scientists Who Supported Light Theories Which scientists supported the idea that light is made of streams of particles? Check all that apply. Albert Einstein Christiaan Huygens Heinrich Hertz Isaac Newton Thomas Young

1, & 4

A photon has a frequency of 2.9 × 10-16 Hz. Planck's constant is 6.63 × 10-34 J•s. The energy of the photon, to the nearest tenths place, is × 10-49 J.

1.9

Which phenomena support only the particle theory of light? Check all that apply. reflection bending around objects traveling in a straight path interference photoelectric effect

3, & 5

What is the energy of a photon of ultraviolet radiation with a frequency of 4.4 × 1015 Hz? Planck's constant is6.63 × 10-34 J • s. 2.9 × 10-18 J 2.9 × 10-34 J 2.9 × 10-48 J

A. 2.9 × 10-18 J

Which concept explains why frequencies of light that fell below the frequency threshold of the metal did not eject electrons? Photons of different kinds of light carry different amounts of energy. Photons are absorbed by atoms as soon as light strikes the metal. Photons of light that has a frequency below the frequency threshold will not eject electrons.

A. Photons of different kinds of light carry different amounts of energy.

Which describes a relationship when calculating the energy of a photon? The energy of the photon is directly proportional to frequency. The energy of the photon is inversely proportional to frequency. As the energy of the photon increases, Planck's constant increases. As the energy of the photon increases, Planck's constant decreases.

A. The energy of the photon is directly proportional to frequency.

The chart shows the frequencies of certain colors of visible light. Which colors will eject electrons when they strike sodium, which has a frequency threshold of 5.7 × 1014 Hz? violet and green red and orange violet only red, violet, green, and orange

A. Violet and green

Which result would support the particle theory of light? Increasing the intensity of the light causes electrons to be ejected. Frequencies of light that fall below the frequency threshold of the metal do not eject electrons. There is a time gap between when light strikes the metal and when electrons are ejected.

B. Frequencies of light that fall below the frequency threshold of the metal do not eject electrons.

As part of the photoelectric effect, which of these is responsible for the pixels in an image on a digital camera? accumulated electrons that are absorbed by the image sensor accumulated electrons that are ejected by the image sensor accumulated photons that are ejected by the image sensor accumulated photons that are absorbed by the image sensor

B. accumulated electrons that are ejected by the image sensor

The energy of a photon was found to be 3.38 × 10-19 J. Planck's constant is 6.63 × 10-34 J • s. Which color of light corresponds to this photon? violet green yellow red

B. green

What is the energy of a photon of infrared radiation with a frequency of 2.53 × 1012 Hz? Planck's constant is 6.63 × 10-34 J • s. 1.68 × 1023 J 1.68 × 1047 J 1.68 × 10-21 J 1.68 × 10-45 J

C. 1.68 × 10-21 J

A photon has 3.4 × 10-18 joules of energy. Planck's constant is 6.63 × 10-34 J•s. What is the frequency of the photon? 5.12 × 10-15 Hz 1.95 × 1016 Hz 5.12 × 1015 Hz 1.95 × 10-16 Hz

C. 5.12 × 1015 Hz

Which statement best describes how today's scientific community views light? Light behaves only like waves. Light behaves only like particles. Light behaves like both waves and particles.

C. Light behaves like both waves and particles.

Which ancient idea of the nature of light did Isaac Newton build upon? Light is a wave or disturbance that travels through spaces in the air. Light is a stream of rays that comes with great velocity from the eyes of an observer. Light is a substance through which particles flow from a light source.

C. light is a substance through which particles flow from a light source

Which order shows increasing energy of photons? gamma rays, visible, infrared, microwaves infrared, gamma rays, microwaves, visible microwaves, infrared, visible, gamma rays visible, microwaves, gamma rays, infrared

C. microwaves, infrared, visible, gamma rays

Match each concept to the scientist who supported it: Christiaan Huygens Heinrich Hertz James Clerk Maxwell Isaac Newton Thomas Young

Christiaan Huygens: Light is a wave because it bends when it hits barriers and openings Heinrich Hertz: Light is a wave that has similar properties as radio waves James Clerk Maxwell: Light is a wave made of electric and magnetic fields Isaac Newton: Light is made of particles because it travels only in straight paths Thomas Young: Light is a wave because this property can explain interference

What is the energy of a photon with a frequency of 3.6 × 1015 Hz? Planck's constant is 6.63 × 10-34 J•s. 1.8 × 10-49 J 2.4 × 10-19 J 1.8 × 10-18 J 2.4 × 10-18 J

D. 2.4 × 10-18 J

What is the formula for calculating the energy of a photon? E = h - f E = E = h + f E = hf

D. E = hf

Which observation supports the idea that light is made of particles? Light is produced by the interaction of magnetic and electric fields. Light spreads out after passing through an opening. Light diffracts when it hits a barrier. Light moves in a straight path.

D. Light moves in a straight path.

Match each behavior of light waves to the correct definition

Reflection: bouncing off of light as it encounters surfaces Diffraction: bending of light as it encounters objects and openings Refraction: bending of light as it passes from one medium to another medium

Why do scientists believe that light is made of streams of particles?

Scientists believe that light is made of streams of particles because only the presence of photons can explain phenomena observed during experiments on the photoelectric effect. These observations include only some frequencies of light causing the ejection of electrons, no time gap existing between light striking a metal and electrons being ejected, and intensity having no effect on the kinetic energy of the ejected electrons.

Why do scientists believe that light is made of waves?

Scientists believe that light is made of waves because experiments have shown that, based on Huygens's principle, waves have the ability to bend and change direction. This behavior of waves explains diffraction and interference.

Identify the theory that can be used to explain each phenomenon. Diffraction: Interference: Reflection: Refraction:

wave theory wave theory both particle and wave theories both particle and wave theories

Complete the sentence to describe how light behaves as it relates to its nature (waves or particles). Light travels as and interacts with matter as .

waves particles