Nuclear Physics Definitions Flashcards
(26 cards)
What is Alpha particle?
A positively charged particle consisting of two protons and two neutrons. They are highly ionising but can be stopped by a few centimetres of air.
What is Atom?
The smallest component of an element having the chemical properties of the element, consisting of a nucleus containing combinations of neutrons and protons and one or more electrons bound to the nucleus by electrical attraction.
What is Electrons?
A negatively charged constituent of the atom, that are found in different energy levels, around the nucleus.
What is Ion?
An atom which has lost or gained electrons to obtain an overall charge.
What is Neutrons?
A neutral particle in the nucleus of an atom. Their quantity varies between isotopes of the same element and can be found by subtracting the proton number from the nucleon number.
What is Nuclear model?
The model developed from Rutherford’s alpha particle experiment, with the central nucleus as a small, positively charged area harbouring all the atom’s mass, and electrons orbiting around this.
What is Proton?
A positively charged particle in the nucleus of an atom. There are the same number of protons as electrons in a neutral atom, balancing their charges.
What is Isotopes?
Atoms with the same number of protons but different numbers of neutrons. The atomic number is the same, but the mass number is different.
What is Nucleon number?
The number of protons and neutrons in an atom.
What is Nucleus?
A collection of particles called protons, which are positively charged, and neutrons, which are neutral.
What is Nuclide?
Refers to an atom with a distinct number of protons and neutrons in its nucleus.
What is Nuclide notation?
A shorthand method of showing information about atoms.
What is Proton number?
The number of protons found in an atom of a specific element. Each element has a different proton number.
What is Background radiation?
Radiation that is found in small quantities all around us.
What is Corrected count rate?
The background radiation count produced solely from the source being investigated. Found by subtracting the count when the source is not present from the count when it is.
What is Count rate?
The number of counts of radiation per second (units = Bq) or per minute.
What is Ionising radiation?
Radiation capable of removing electrons from atoms, to form ions.
What is Radioactivity?
When unstable atoms give radiation that can be harmful to humans.
What is Radiation?
The energy emitted as electromagnetic waves or as moving subatomic particles (alpha, gamma, or beta).
What is Beta particle?
A high-speed electron that a nucleus emits when a neutron converts into a proton. They are ionising but can be stopped by a thin sheet of aluminium.
What is Gamma ray?
Electromagnetic radiation emitted from a nucleus. They have a very high penetrating power and can penetrate up to several centimetres of lead.
What is Random nature of radioactive decay?
You cannot predict which nuclei in a radioactive sample will decay next, or when the next decay will occur – it is a random process.
What is Radioactive decay?
The random process of unstable nuclei emitting radiation to become more stable. During α- or β-decay the nucleus changes to that of a different element.
What is Half-life?
The time it takes for the initial count rate of a sample of an isotope to halve (different for different isotopes).
