Topic 7 Radioactivity and Particales Flashcards
Describe the structure of the atom in terms of protons neutrons and electrons.
Mostly empty space. In the centre there is a very small and dense nucleus made of protons and neutrons. Electrons occupy the empty space that makes up the rest of the atom. The atom is 10000 times larger than the nucleus.
What is radioactivity?
The decay of a nucleus in form of energy or particle emitment.
What does the (mass) nucleon number tell us?
The number of protons and neutrons there are in the nucleus of an atom.
What does the atomic (proton) number tell us?
The number of protons there are in the nucleus of an atom.
Name 3 types of radiation in order of their ionising power.
Gamma, beta, alpha.
What is an isotope?
An atom of the same element that has the same number of protons and different number of neutrons (hence a different nucleon number).
What is alpha decay?
When a nucleus contains too many nucleons and it decays by emiting an alpha particle(2 neutrons and 2 protons).
Fill in the gap:
alpha particles, beta particles and gamma rays are ________ _________ emitted from _________ nuclei in a random process.
ionising radiation
unstable
What is alpha emision?
When a nucleus contains too many nucleons and it decays by emiting an alpha particle.
What is beta decay?
When a nucleus contains too many neutrons, so a neutron changes into a proton and a high-energy electron is emitted.
What is a beta particle?
A high-energy electron.
What is gamma emision?
The emision of x-rays and gamma rays because a nucleus has undergone alpha or beta decay and the nucleons within the daughter nucleus are often in an excited state.
