Unit 1: Radioactive Decay Flashcards
What is an isotope?
Atoms with the same number of protons but differing numbers of neutrons
What do protons define?
An element, if you know the number of protons, you know the element.
What does the number of neutrons determine?
The stability of the nuclei
What is Carbon-14
Decomposes
It is unstable and decomposes naturally into different constituents
What happens in a chemical reaction?
Valence electrons, nucleus, isotopes
- Change in valence electrons
- No change in nucleus
- Independent of isotopes
What happens in nuclear reactions?
Atomic nucleus, element, potential energy
- Change in the atomic nucleus
- Produces new element
- Varies dramatically by each isotope
- Could change the number of neutrons or protons
- Large amounts of potential energy
What is the rate of nuclear reactions unaffected by?
Location, laboratory
- Typical laboratory temperatures, catalyst, pressure, etc
- Atomic location
How does the decomposition of the nucleus happen?
The decomposition of the nucleus can’t be influenced, it happens irrespective of the environment and is constant so it can’t be sped up or slowed down.
What happens in alpha decay?
Breaking down
The nucleus is breaking down and gives off an alpha particle similar to a helium atom.
What is an alpha particle?
An alpha particle is a helium atom that has lost 2 electrons so its given as 2+
What decay occurs when a nucleus has too many protons?
When an nucleus has too many protons it undergoes beta + decay.
What is the mass number?
The larger number
What is the atomic number
The smaller number - number of protons and electrons
What happens to the mass number and atomic number in the product of alpha decay?
The product nucleus has an atomic number that is two less, and a mass number that is four less, than the original nucleus
What happens in beta decay?
A neutron is converted to a proton and an electron is ejected.
What happens to the mass number and atomic number in the product of beta decay?
The product nucleus has an atomic number that is one more than the original nucleus. The mass number remains the same.
What happens to the mass number and atomic number in the product of beta decay?
The product nucleus has an atomic number that is one more than the original nucleus. The mass number remains the same.
What is a positron?
Positron = electron with positive charge
What happens to the mass number and atomic number in the product of positron emission?
The product nucleus has an atomic number that is one less than the original nucleus. The mass number remains the same.
What is electron capture?
When another orbital electron fills the vacancy in the inner-shell and an X-ray photon is emitted.
What happens to the mass number and atomic number in the product of electron capture?
The product nucleus has an atomic number that is one less than the original nucleus. The mass number remains the same. E.g. potassium-40 decay
Why does gamma emission occur?
In some cases radioactive decay results in a product nucleus in an excited state which goes to a lower state with emission of electromagnetic radiation
What is spontaneous fission?
A heavy nucleus splits into lighter nuclei with the release of energy
