The use of ultraviolet (UV) light in water treatment has been studied for many years. Recent studies have focused on developing efficient technologies to treat water using UV light.
Ultraviolet (UV) radiation is a wavelength of electromagnetic radiation, consisting sometimes of just a single photon, and other times of a packet, or stream, of photons.
Photons are the fundamental particles of light. As described by Einstein’s theory of relativity, photons are constrained to carry only certain quantities of energy: quanta with an integer number of electrons, called quantum levels or energy levels.
These energy levels determine how much energy each photon can carry. The higher the energy level, the more kinetic (motion) force the photon carries. Less kinetic force means less damage to molecules it encounters.
Definition of an electron
An electron is a negatively charged subatomic particle. Electrons belong to chemical element atoms, and each atom has a fixed number of electrons.
Atomic numbers are the number of protons in an atom. Atomic masses are the total number of protons and neutrons in an atom.
Both atomic numbers and atomic masses determine an atom’s properties, including its ability to be chemically reactive. Changes in either of these numbers will result in a new element.
The concept of an electron is related to the concept of charge. Charge can be thought of as the “measurement” of electrons. One charge is equal to one electron. One electron charge = -1 Electron charges are what define an element.
Energy of a photon
A photon is a unit of energy that comes in several different flavors, or wavelengths. All photons have the same basic properties, but each one has a different amount of energy.
Photons can be gamma rays, x-rays, ultra-violet (UV) rays, visible light, and infrared (IR) radiation. Each of these has its own specific wavelength or frequency.
The higher the frequency or shorter the wavelength, the higher the energy of the photon. This is why UV photons are more harmful to your skin than IR photons are. UV photons have higher energy.
In order to answer our question—What wavelength of light contains enough energy in a single photon to ionize a hydrogen atom?—we need to know how much energy a photon contains.
Mass of an electron
Along with the electron number, the mass of an electron is important in determining what kind of ionization occurs. If the ionization involves stripping an electron off of a molecule or atom, then the ionization event requires enough energy to separate the electron from the atom or molecule it is attached to.
Ionization can occur in three different categories: weak, strong, and doubly strong. Weak ionization occurs when a photon with enough energy hits an electron and deflects it. This happens when the photon has less energy than the required separation energy between the electron and atom.
Strong ionization occurs when a photon with enough energy hits an electron and removes it entirely. This happens when the photon has more energy than the required separation energy between the electron and atom.
Doubly strong ionization occurs when a photon with enough energy hits two electrons at once and removes them both. This happens when the photon has more energy than double the required separation energy between electrons and atoms.
Calculate the minimum energy needed to ionize hydrogen
To understand what wavelength of light contains enough energy in a single photon to ionize a hydrogen atom, we first need to understand what an atom is.
Atoms are the smallest unit of a chemical element, like hydrogen or helium. An atom is composed of protons, electrons, and neutrons. Protons and neutrons are found in the nucleus of the atom, while electrons orbit around the nucleus.
Electrons are very light particles that have a negative charge. When photons of light hit an electron, it will get kicked out of its normal position and receive a lot of kinetic energy.
To find out how much energy it receives, we need to know two things: its mass and the speed at which it is moving. Since the electron is very small, we can assume its mass is negligible compared to a whole hydrogen atom. Therefore, only its speed will matter in this calculation!
To figure out how much kinetic energy the electron receives, we use the formula: .
Red light vs. violet light
Red light has longer wavelengths than violet light. Because of this, red light contains photons with less energy per photon than violet light.
Because of this difference, red light requires more photons to transfer the same amount of energy to a hydrogen atom, breaking its bond.
Because of the nature of atoms, they contain inner shells containing only a certain number and type of electrons. These shells are defined by their level of stability, or how difficult it is for an electron to be displaced from its shell.
When a photon of enough energy encounters an electron, it will be dislodged from its shell and escape the atom. This is what causes ionization in atoms.
What are the fundamental elements?
In the period spanning from the first few seconds after the Big Bang until about one second later, quarks combined into up and down quarks, which combined into protons and neutrons, which combined into helium nuclei.
These are the three known generations of particles, or families. Each generation consists of particles with similar properties, such as mass and behavior. Particles can belong to more than one generation, as is the case with some bosons.
At present, scientists have not been able to produce any known particle families in the lab, but this does not mean that they do not exist. It just means that we have not yet discovered how to create them.
Some of these fundamental elements may prove to be non-elementary, or composite in nature.
Can all elements be used as lasers?
Currently, only a few elements can be used to lase, or produce laser light. These include helium-neon (HeNe), caesium, and argon. Other gases have been tried, but they have not been successful as laser gases.
All of these lasers require a continuous flow of atoms or molecules entering the lasing cavity to sustain the laser. Because of this requirement, they are termed continuous-flow lasers.
Helium-neon (HeNe) lasers use helium and neon gas to produce a line of light with a specific color (frequency). Caesium lasers use atoms of caesium as the lasing molecule. Argon lasers use…you guessed it! Argon as the lasing molecule.
What is laser therapy used for?
Laser therapy is a form of light therapy that is being researched for a variety of applications. Some of these applications include pain management, the healing of wounds and injuries, and the promotion of cell growth.
Laser therapy is not one specific treatment. It is a term used to describe the use of laser radiation directed at a region or tissue to provide a therapeutic effect.
The way this works varies depending on the laser used and the desired effect. In general, radiation in the form of light is delivered to a targeted region or tissue in an intentional way. This contributes to health benefits by improving or altering local environment or cell activity.
There are many wavelengths of light that can be used for laser therapy. All have different effects on cells, depending on what element they affect.