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Physics 1
Neutrons help stabilise the nucleus, and help create the strong nuclear force.
Strong nuclear force:
- Holds together the subatomic particles of the nucleus (protons and neutrons)
Half life:
- Time required for one-half of the atomic nuclei of a radioactive sample to decay
Radiation: Energy that travels through space at the speed of light
3 Types of Radiation:
Research: Nuclear fission vs Nuclear fusion
- Nuclear fission: A process in which the nucleus of an atom splits into two or more smaller nuclei as fission products, and usually some by-product particles.
- Nuclear fusion: A reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles
Research: Advantages/Disadvantages of nuclear energy.
Internet Investigation
- What is a radioisotope?
- A radioactive isotope.
- Radioactive: The emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles which cause ionisation.
- Isotopes: atoms with the same atomic charge(number of protons), but different atomic mass(number of neutrons).
- They are unstable, and are able to decay.
- Unstable: When the strong nuclear force (SNF) and the repulsive force between protons are unbalanced, specific when SNF is weaker
- "When the strong nuclear force is less than the electrostatic force of repulsion between protons and neutrons, there is not energy to hold the isotope together, resulting in an emission of energy which breaks down the nucleus."
- What happens when a radioisotope decays?
- Radioisotopes are unstable, and achieve stability, by shedding excess particles and energy through radioactive decay.
- The time period for radioactive decay is unique to every isotope, and measured through its half-life, which is the time taken for half of the radioisotopes to undergo radioactive decay.
- When radioactive decay occurs in a radioisotope, particles are emitted via alpha, beta and gamma decay, alongside electron capture.
- Other than gamma decay and the conversion of an electron to a less excited state, radiation decay produces daughter atoms with a different number of protons or neutrons.
- Isotope tries to get to a more stable form, through one or more stages of radiation decay. This always produces gamma radiation.
- e.g. Carbon-14 beta decays to Nitrogen-14.
- What is produced when a radioisotope decays?
- It depends on the type of decay that occurs. For example, in Alpha decay, a helium-4 atom is released.
- What are the characteristics of the three main types of radiation
Fred stuff
List significant radioactive sources and isotopes used in agriculture.
-Heat up water without producing CO2
-PCR tests to rapidly detect diseases in livestock
-The addition of Nitrogen-15,
A stable isotope that is used to determine the fertiliser use efficiency of crops. Additionally it is used to quantify the amount of Nitrogen that crops can acquire from the atmosphere through biological Nitrogen fication
-The sterile insect technique (SIT)
Is among the most environmentally friendly insect pest control methods ever developed. Irradiation by means of gamma rays and X-rays is used to mass-sterilise plots of land leading to insects that are incapable of producing offspring
-Food safety and control
Ionizing radiation can be applied to food in order to kill harmful microbes preventing foodborne illness
-Plant breeding and genetics
Seeds can be irradiated with Gamma rays and X-rays to initiate genetic changes that are advantageous for consumption
Half-life
The time taken for the radioactivity of a specified isotope to fall half to its original value
