History Atomic Theory
1. Construct a timeline which shows the development of the Modern Atomic Theory. Include a minimum of 5 and a maximum of 10 significant events in your timeline.
2. Choose one scientist involved in the development of the Atomic Theory and describe how their work made a significant contribution to its development.
A scientist involved in the atomic theory was John Dalton. His theory was:
· Matter comprises of very small particles called atoms.
· Atoms that are identical in size, mass and other properties are of the same element.
· It is not possible to subdivide or create/destroy atoms.
· When atoms of different elements are combined they form chemical compounds. These chemical compounds can be divided into two categories.
· Atoms are combined, separated/rearranged in a chemical reaction.
John Dalton’s work made significant contribution to the development of the atomic model because he created a basis of the atom, theories that other scientists could experiment on. For example we now know that atoms of the same element do not have the same mass and properties. That was proven from the discovery of isotopes. An isotope is an atom of the same element but with different masses and properties. We would never have made the discovery of isotopes if Dalton had not stated that atoms of the same element have identical properties because no one would have tested it and proved it wrong. Dalton’s theories were used by other scientists to branch off and development on his theory whilst making new discoveries.
3. In terms of Atomic Theory, compare nuclear fusion and fission reactions providing an explanation of a named example of each.
Nuclear fission is when a large, heavy nucleus splits into two lighter ones this only occurs when when neutrons hit two isotopes. The two isotopes are uranium-235 and Plutonium-239. This occurs as a chain reaction in a nuclear power plant. Nuclear fusion is the opposite to fission it is where two lighter nuclei join to form a heavier one. Fission requires high very high temperature (over 4,000,000°), it is difficult to obtain and nearly impossible to control this is why it occurs in the sun.
4. Discuss the development of the Large Hadron Collider (LHC) and how it has led to an advance in scientific understanding. Present your personal opinion on how you think the technology will be further developed.
The Large Hadron Collider (LHS) is the world’s most famous science experiment and is the world’s largest particle accelerator. It is one of the most complex machines created in the history of science. A group of over 10,000 scientists, working for the European Orginisation for Nuclear Research, were involved in its development over a ten year period from 1998 to its completion in 2008. It’s first experiment was completed on the 10th September 2018.
It is located in the French and Swiss countryside, actually buried 100 metres underground. It is a ring with a circumference of 27 kilometers. The LHC has recorded the highest energies ever achieved in a laboratory when two beams of protons collided together.
There have been set backs along the way, one notable one occurring on the 22nd September 2008 when 50 of the LHC’s magnets, there is a total of more than 6,000 magnets, were damaged. The LHC was unable to conduct any further experiments until repairs were completed in 2010.
The development of the LHC is very important to the scientific world and the machine proved it’s worth in 2013 when it confirmed the existence of the Higgs Boson particle (first predicted by scientist in 1964). This is one of the key theories about the way the universe works.
There are currently a further 6 experiments underway at the LHS with scientists from six continents and over 100 countries working together. The results of these experiments are hopefully able to provide further insight and understanding into the nature of the most basic building blocks of the universe and how they interact together.
Results from experiments held at the LHS have led to improvements and greater understanding of many things in our everyday life. I think one of the best developments has been in the treatment of cancer.
It’s estimated that globally 42 million people are affected by cancer around the world. So any improvement in ways to fight cancer can have significant effects globally. Particle acceleration is used in PET scanners, accelerated electrons are fired onto targets to
5. Discuss one benefit and one concern of nuclear energy as a power supply.
A constant power supply is one benefit of nuclear energy. Other types of power such as solar and wind depend on natural elements of sun and wind to be able to create electricity. Nuclear energy can be produced 24 hours every day. Disposal of radioactive waste is one of the biggest concerns with nuclear energy. High-level radioactive waste can cause damage to living things and will corrode any compartment that holds it. These things make it very difficult to store and especially to transport. Over time the waste can achieve a safe radioactive level but this process can take hundreds of years.
6. Discuss the use of a radioactive isotope in an application of nuclear medicine.
Nuclear medicine can be used to provide information about specific organs in a patient’s body and how to treat them. It can be used to treat medical conditions, commonly cancer, where it targets particular cells to weaken or destroy. Another important use of radioisotopes is the sterilization of medical equipment. Over 40 million nuclear medicine procedures occur annually with the demand increasing by 5%.