# General Physics of Atomics

Edited by Jen Moreau

## ATOMIC

### INTRODUCTION

At the end of 19th century, it was thought that almost all of physics might have been fully explained by mechanics, electromagnetism, and thermodynamics. At that time, only a few minor problem are remained to be resolved or otherwise, physics was believed to be almost complete. The nature of the problem is that there was no form of communications between the field of Mechanics, Electricity, and Magnetism. There were also some effects that lack explanation, but nonetheless, they never affect weaponry, agriculture, and machinery. The problem faced at that time can be stated in three statements

• The speed of light remain constant in all frames of reference
• All the laws of nature were the same in all inertial frame of reference.
• Galilean transformation of absolute time and coordinate.

All these statements contradict one another. One has to be dropped to solve the problem.

### THE THEORY OF RELATIVITY

• All inertial frames of reference are equally suitable for the physical phenomena description.
• Speed of light in vacuum is the same for all observers and it is dependent on the source's motion
• The tool for this is a Lorentz transformation of space-time with a set of consequences.

The three big problem with a light that was not resolved are:

• Atomic spectra
• Photoelectric effect

Bodies emit heat radiation that is dependent on their temperature.

### PHOTO ELECTRIC EFFECT

Whenever light shines on metal, the surface of the metal may become positively charged. This is due to the electrons gain energy from the light wave that shines on it and is able to leave the surface of the metal.

## SPECTRA

The difference between the spectra emitted by the discharge tubes and the spectrum emitted by a regular light bulb are:

• Spectra emitted by the discharge tubes display distinctive line colors: EMISSION LINE SPECTRA.
• Spectrum of light bulb are a continuous band of colors: CONTINUOUS SPECTRUM
• It is the light emitted due to the filament temperature (Black body radiation).

### ABSORPTION SPECTRA

This was explained firstly by Max Planck. The assumption was that light is emitted in portions called quanta. Energy in each quantum is proportional to its frequency as illustrated in the equation below.

E = h f,

Where h = 6.626 * 10-34 Js

F= the frequency of oscillating atoms.

## PHOTONS

### PHOTONS PARTICLES AND WAVES

Photons displays properties of waves and particles

• Properties of waves such as frequency, wavelength, polarization, refraction, diffraction, etc
• Properties of a particle such as carrying linear momentum = h/λ, carrying a quantum of energy =hf.

APA (American Psychological Association)
General Physics of Atomics. (2017). In ScienceAid. Retrieved Feb 27, 2024, from https://scienceaid.net/Atomic

MLA (Modern Language Association) "General Physics of Atomics." ScienceAid, scienceaid.net/Atomic Accessed 27 Feb 2024.

Chicago / Turabian ScienceAid.net. "General Physics of Atomics." Accessed Feb 27, 2024. https://scienceaid.net/Atomic.

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## Article Info

Categories : Atomic