When you think of nuclear weapons, the first image that may come to mind is a large, bellowing mushroom cloud rising high up into the air - something like that which occurred in the World War II bombing of Nagasaki, Japan in 1945.
Nuclear weapons still exists today, though their visibility and danger may not be as obvious as a mushroom cloud. Countries such as the United States, Pakistan and North Korea have publicly admitted to having used nuclear weapons for testing or demonstration purposes, many times in remote areas such as oceans or underground sites.
Most recently, Iran has been creating quite a stir by not obeying the UN's demands to halt uranium enrichment and reprocessing — something commonly used for nuclear reactors but also in making nuclear weapons.
Did you know? In 2005, it was estimated that there are at least 29,000 nuclear weapons held by at least eight countries.
But just what are we talking about when we speak of nuclear weapons? How are they created? How can they be so destructive?
The Makeup of an Atom
Everything is made up of atoms. These particles contain a nucleus, which is made up of neutrons and protons, and are surrounded by a cloud of orbiting electrons. The neutrons and protons have a very strong force holding them together, called a nuclear force, which when broken or formed, can cause a large change in the energy state.
When nuclei come close enough together, reactions between the nuclei can occur, causing the energy, structure, or makeup of atomic nuclei to be changed. It is this type of reaction by which the destructive force of nuclear weapons comes from.
There are two main types of nuclear weapons: fusion and fission bombs and they differ based on how their energy is produced.
Fusion bombs, also known as hydrogen or thermonuclear bombs, produce energy by fusion of lighter atomic nuclei into a heavier nucleus. Nuclear fusion is actually a naturally occurring process, a well known example being the reactions that occur in stars like the Sun, but have also been able to be produced by scientists in the lab.
Did you know? A fusion reaction can create a million more times the amount of energy than a typical chemical reaction.
The amount of energy released in this type of reaction is very large. This is because the sum of the masses of the product nuclei is less than the sum of the masses of the initial fusing nuclei. Basic chemistry tells us that energy cannot be created or destroyed, while Einstein's famous equation, E=mc2, tells us that energy (E) is proportional to mass (m). So, the change in mass of the fusion reactants is lost as energy through the fusion products.
The other type of nuclear bombs is fission bombs, also called atomic bombs, which produce their energy through nuclear fission reactions.
Did you know? Nuclear power plant reactors rely on fission reactions to produce energy.
In these reactions, a massive atomic nucleus of a material, such as uranium or plutonium, is bombarded with neutrons causing the nucleus to split apart into two nuclei. Here, it is the very large repulsive electrostatic forces between the large numbers of positively charged protons in the nucleus that overcomes the strong attractive nuclear force which holds the nucleus together to cause the split.
The neutrons that are produced in this reaction then bombard other nuclei, which then split and bombard other nuclei, and so on, creating a nuclear chain reaction. Like fusion reactions, nuclear fission reactions produce a large amount of energy as the masses of the products is less than the mass of the fissioning nucleus.
Did you know? The amount of energy released by fission bombs can be as little as less than a ton of TNT or as high as 500,000 tons of TNT!
Much of the research and development of nuclear technologies occurs in facilities where strict regulations are put in place to make sure that the research is conducted for peaceful purposes only and that countries do not to test, manufacture, produce, receive, possess, store, deploy or use nuclear weapons.
Amy studied Molecular Biology and just finished her PhD in a breast cancer research lab. She does her part to help the environment by using her bike to get around, buying local produce, and reusing old shopping bags.