More than 120 years ago, Max Planck formulated the mathematical theory of quantized energy in his endeavor to explain black body radiation. His hypothesis led him to create the formula E = hν. "E" stands for energy, while "h" represents Planck's Constant, and "v" represents the frequency of radiated energy. Then, in 1905, Einstein discovered we could expand Planck's model to better explain the photoelectric effect. At the time, Planck and Einstein referred to the phenomena they observed as "quanta." The term "photon" was later coined in a 1926 letter to Nature from Gilbert Lewis, and the scientific community quickly adopted it.

## What is Quantized in Chemistry?

In the field of quantum mechanics, quantization is the concept of a system being limited to certain specific energy values (states) due to their occurrence at finite probabilities. The states depend on what type of system you're dealing with.

## Is Energy Always Quantized?

No. Kinetic energy is more than just a single point. It can't be quantized because it always appears as a continuous spectrum in the spectrum of Hamiltonian, which describes total energies for any given system. Kinetics is an example that proves this rule and shows how kinetic motion doesn’t follow traditional rules like conservation laws or statistical mechanics but instead occurs at different frequencies depending on what's happening within its own boundaries.

## What Energy is Quantized?

Some systems are quantized, meaning they can only have certain energies and not an infinite range like classical mechanics. This would be like how some cars travel at particular speeds because their kinetic energy has finite values. This type of energy is known as atomic, quantum, or discrete energy.

While this may sound confusing, we actually encounter quantized energy often in our day-to-day lives. For example, a musical instrument is limited in the number and range of notes it can produce. Since the instrument cannot produce an infinite range of notes, it is quantized. Finally, money is another great example of quantization. Many currencies, including the US dollar, are broken down into fractions. You can spend a fraction of a dollar, but the smallest increment possible is a single penny. As such, you can't spend a fraction of a penny, so it is quantized.

## Which Energy is Not Quantized?

Free particles can have infinite, continuous kinetic energy and are therefore an example of a type of energy that is not quantized.

## What Can Quantized Energy Be Used For?

Quantization can be used to represent particles with discrete values for their energy. This works well with many theories that are based on particles, such as quantum mechanics. In fact, they wouldn't make sense without using quantized energy.

What Factors Influence Quantized Energy?

Energy quantization depends on what part of the electromagnetic spectrum you're looking at. For example, some parts of the spectrum, such as X-rays and gamma rays, cannot be absorbed by materials that have low atomic numbers. If they can't be absorbed, then their energies must be conserved for long periods of time. This is why you need lead to block gamma rays--they provide an impenetrable barrier that prevents gamma rays from being absorbed.

Light waves are the most common example of quantized energy because they're actually quite complex. Light can also be considered a transverse wave, which means it has both electric and magnetic components. Photons are the fundamental units of energy in light waves. A photon is incredibly small; in fact, photons can't be measured without quantum mechanics.

## Is Frequency Quantized?

No, frequency is not quantized. It has a continuous spectrum. However, if a particle is confined by a given possibility, then it is discrete.