By: Khushi Gupta
The science behind superpowers in comics can be quite interesting to look at, especially in the case of Bruce Banner and how a single experiment turned him from a soft-spoken scientist to a rampaging green monster. Bruce Banner, or the Hulk, was first seen as a comic book character created by Stan Lee, Jack Kirby, and Paul Reinman, but is now commonly associated with Mark Ruffalo, the actor who portrays him in the movies. There are many versions of its origin but the movie plot goes like this: Bruce spends about 18 months in a Gamma Lab, hoping to recreate the super serum used on Captain America, believing that gamma radiation was the key to the transformation. But what is radiation?
To learn about radiation, one must first have a basic understanding of chemistry. Atoms (made up of electrons, protons, and neutrons) are the building blocks of chemistry. Atoms pertain to what element it is, although there can be multiple versions of an atom for a certain element. We call these isotopes. In each isotope, the structure of the nucleus changes. For example, helium has 2 stable and common isotopes: Helium-3 and Helium-4. The main difference between the two isotopes is that Helium-3 has one less neutron than Helium-4. However, some isotopes have an imbalance of protons to neutrons, making them unstable or radioactive. To become stable, they go through different types of decay based on what they need to add or get rid of and emit electromagnetic radiation. This process is known as radioactivity.
Most of the radiation that we encounter stems from our natural environment, originating from the Earth. The higher up in the atmosphere you go, the more intense the radiation is. All elements with atomic numbers that are greater than 82 are radioactive and can emit 3 different types of radiation.
Alpha radiation is one form of radiation and is symbolized by the Greek letter 𝛂. Alpha particles have a positive charge and are made up of a combination of two protons and two neutrons. Think about Helium without the electrons. This radiation is relatively easy to shield due to its “large” size, which gives it a low velocity and double positive charge. It can, however, cause significant damage to a material’s surface, like living tissue, because of its great kinetic energy. Even with this, external radiation is not a direct health hazard as our skin has many layers and the radiation can generally be stopped before reaching the sensitive layers of skin. Problems occur only if the material emitting the alpha radiation is inhaled, swallowed, or absorbed within the body. When travelling through air, it can pick up electrons and become a harmless helium atom.
Beta radiation is another type of radiation and can be symbolized by the Greek letter β. Not to be confused with electrons surrounding the nucleus that make up the rings or electron cloud, Beta particles are electrons that were ejected from the nucleus. A neutron is made up of two parts: a positron and an electron. The positron has a positive charge while the electron has a negative, which is why a neutron has a neutral or no charge. In beta radiation, the electron within the neutron is ejected, making the neutron become a proton and have a negative charge. It is a stream of charged particles that are emitted at a velocity close to light speed. As it has a low mass, pairings between beta particles and other atoms are less frequent than pairings for alpha particles. This also means that these particles are able to travel a further distance. Internal organs are generally safe from beta radiation but exposed organs can be sensitive. Once these particles are stopped, it gets absorbed and becomes part of the material they are in.
Gamma rays are the last type, and what Bruce Banner used. These can be identified by the symbol 𝛄. Gamma rays are high electromagnetic frequency radiation that have no charge but are extremely pure and possess large amounts of energy. Gamma radiation can be seen as “invisible light” due to its stream of particles that can pass through the electromagnetic field undetected. They can penetrate almost all items except for very dense materials. Radiation on the body can cause health hazards as the rays are not as affected by travelling through air like beta or alpha particles. For those reasons, it can create severe damage to cells and cause mutagenesis, the creation of mutations in DNA molecules, even when not taken internally. It can occur naturally such as changes in DNA structure or can be caused by environmental exposure to genotoxins (chemicals that can change DNA structure). It is an irreversible process that can affect organisms, which is why it can be of concern.
Q. What is radioactivity?
A: Radioactivity, also known as radioactive decay or nuclear decay, is a process that unstable isotopes go through in order to become stable. In this, spontaneous emissions of radiation are released and are either alpha, beta, or gamma.
Q: Which radiation is similar to a helium atom? Why?
A: Alpha radiation is similar as it consists of 2 neutron and 2 protons, similar to Helium’s nucleus.