IB MYP Integrated Sciences e-Assessment : Nuclear energy
Exam Style Practice Questions - New Syllabus
Question (8 marks)
According to the United States Institute for Energy Research, 19.5% of the electricity produced in the United States in 2015 came from nuclear power plants. Uranium is the fuel most widely used to produce nuclear energy. Uranium has an atomic number of 92. It mainly comprises two isotopes, uranium-238 and uranium-235.
Question a (2 marks)
Outline the meaning of the term isotope.
▶️Answer/Explanation
Isotopes:
Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons. This results in isotopes having the same atomic number but different mass numbers. For example, uranium-235 and uranium-238 are isotopes of uranium, both with 92 protons but differing in the number of neutrons.
Question b (1 mark)
Determine the number of neutrons in uranium-235.
▶️Answer/Explanation
Number of Neutrons:
Uranium-235 has 92 protons (atomic number) and a mass number of 235. The number of neutrons is calculated as:
\[ \text{Number of neutrons} = \text{Mass number} – \text{Atomic number} \]
\[ \text{Number of neutrons} = 235 – 92 = 143 \]
So, uranium-235 has 143 neutrons.
Question c (1 mark)
Nuclear energy is released through a nuclear reaction by fission or fusion of atomic nuclei. State what happens in the process of nuclear fission.
▶️Answer/Explanation
Nuclear Fission:
In nuclear fission, the nucleus of an atom splits into two or more smaller nuclei, along with the release of a large amount of energy and several neutrons. This process is typically initiated by the absorption of a neutron by a heavy nucleus, such as uranium-235 or plutonium-239.
Question d (4 marks)
The nuclear industry is highly regulated to minimize the risk of exposure to ionising radiation. Suggest an effect of radiation exposure on each of the following:
- Human health
- Farming
- Environment
- Population
▶️Answer/Explanation
Effects of Radiation Exposure:
1. Human Health:
– Radiation exposure can cause acute effects such as radiation sickness, burns, and long-term effects like cancer, genetic mutations, and damage to organs.
2. Farming:
– Radiation can contaminate soil and water, leading to the absorption of radioactive materials by crops. This can make food unsafe for consumption and harm livestock.
3. Environment:
– Radiation can cause long-term damage to ecosystems, affecting plant and animal life. It can also lead to the contamination of water bodies, making them unsafe for aquatic life and human use.
4. Population:
– Radiation exposure can lead to increased rates of cancer and genetic disorders in the population. It can also cause displacement of people from contaminated areas, leading to social and economic disruptions.