light waves

Dual Nature of Electrons and The Wave Nature of Light

Objectives:

• describe a particle and a wave

• identify key persons and their contribution in the development of the wave-particle duality theory.

• define wave interference, diffraction, dispersion, and scattering;

• differentiate constructive and destructive interference

Multiple Choice

What phenomenon occurs when colors of a rainbow are seen when light passes through a glass prism?

• Scattering of light

• Diffraction of light

• Dispersion of light

• Reflection of light

Multiple Choice

These are all colors of spectrum except:

• Indigo

• Purple

• Blue

• Green

Multiple Choice

Tyndall effect is the scattering of the light by:

• Air particles

• Solid particles

• Liquid particles

• Colloidal particles

Multiple Choice

Wave interference can occur in the following except:

• two rocks are thrown at the same time into a body of water

• the same song played on two speakers

• two different light sources side by side

• light reflected from a film of oil floating on water

Multiple Choice

Why does scattering of light occur?

• Light rays are blocked and reflected to all directions by the clouds or particles in the air.

• Light rays are passing through and refracted to all directions by the clouds or particles in the air

• Light rays are blocked and refracted to all directions by the clouds or particles in the air

• Light rays are passing through and are dispersed by raindrops acting as multiple prisms.

Is an Electron a Particle or a Wave? 

In science, a particle is described as a minute portion of matter and is also referred to as the smallest known building blocks of the universe. This means that everything that makes up matter and universe is called particle. So how can electrons become a wave?

Electron being a wave

In physics, a wave is described as a disturbance that travels through space-time and medium accompanied by transferring energy from one place to another. A medium may be a substance or material that carries the wave. The wave medium is not the wave and it does not make the wave; it merely transports the wave from its source to other locations.

Example of a wave

When the waves meet together, crest meets crests it is called constructive interference. When the waves cancel each other, no interaction at all, it is called destructive interference.

Evidences of Wave-like Behavior of Electrons

Huygen’s Principle explains why light shining through a pin hole or slit will spread out rather than going in a straight line.

Thomas Young studied the interference of light waves using the double-slit experiment. 

August Fresnel supported Young’s experiments with mathematical calculations.

Albert Einstein had proposed a solution to the problem of observations made on the behavior of light having characteristics of both wave and particle theory.

This finding came to be known as the photon theory of light which later led to the conceptualization of quantum mechanics in the twentieth century

Multiple Choice

Which phenomenon best supports the theory that matter has a wave nature?

• Electron momentum

• Electron diffraction

• Photon momentum

• Photon diffraction

Multiple Choice

A minute portion of matter and was known as the smallest building block of the universe.

• Particle

• Photon

• Portion

• Product

Multiple Choice

He proposed the particle theory of light

• Isaac Newton

• Louis de Broglie

• Max Planck

• Thomas Young

Multiple Choice

Which of the following is an example of light behaving like a particle?

• Photoelectric effect

• Doppler effect

• Interference

• Diffraction

Multiple Choice

Wave particle duality best applies in analyzing the motion of ________.

• Projectile

• Space shuttle

• Heavenly bodies

• Electrons

Diffraction, Interference, Dispersion, and Scattering 

• Electromagnetic Waves

• The Double Slit Experiment

• Understanding Light as a Wave

• Light Sources for Interference

• Light Scattering 

• Tyndall effect

• Angle of Deviation

Multiple Choice

An example of dispersion of light is ____.

• Sky looks bright orange in the evening

• Shadow

• Rainbow

• Pool seems shallower

Multiple Choice

Two light sources are said to be coherent if they:

• are of the same frequency.

• are of the same frequency and maintain a constant phase difference

• are of the same amplitude and maintain a constant phase difference.

• are of the same frequency and amplitude

Multiple Choice

What principle is responsible for alternating light and dark bands when light passes through two or more narrow slits?

• Interference

• Scattering

• Diffraction

• Dispersion

Multiple Choice

Why is the spectrum of light separated into its components of color

when white light is directed to a prism?

• The different colors in the white light bend away from the normal line at different angles when entering prism ingestion.

• The different colors in the white light bend towards the normal line at different angles when entering prism.

• The different colors in the white light bend away from the normal at same speed to each other when entering prism.

• The different colors in the white light bend towards the normal at same speed to each other when entering prism

Multiple Choice

Which of the following phenomena does NOT show a difference between the wave theory and particle theory of light?

• reflection

• refraction

• interference

• diffraction

Asynchronous tasks:

Answer WHAT'S MORE on pages 11 & 12 of Module 9 and page 18 of Module 10

Thank you

Have a nice day to all. Keep safe everyone...