19.2 Radioactive Decay

Transmutation

• a reaction in which an atom's atomic number is altered

• a process of combining two elements to form a new one

• a method of measuring atomic mass

• a technique for splitting atomic nuclei

Beta decay

• Changes a neutron into a proton

• Changes a proton into a neutron

• Emits alpha particles

• Releases gamma radiation

Electron capture

• Occurs when the nucleus of an atom draws in a surrounding electron, usually one from the lowest energy level

• Is a process where electrons are emitted from the nucleus

• Involves the absorption of a photon by the nucleus

• Is a type of radioactive decay that releases energy

Nucleons

• The protons and neutrons in an atom's nucleus

• The electrons surrounding the nucleus

• The particles that make up the atomic mass

• The isotopes of an element

Positron

• A particle with the same mass as an electron but an opposite charge

• A particle with a greater mass than an electron and a positive charge

• A particle with the same charge as an electron but a different mass

• A particle with no mass and a negative charge

Strong Nuclear force

• Acts on subatomic particles that are extremely close together, overcoming the electrostatic repulsion among protons

• Is responsible for the attraction between electrons and protons

• Is the force that governs the motion of planets in the solar system

• Is the force that causes chemical reactions between atoms

Radiochemical dating

• The process of determining the age of an object by measuring the amount of a certain radioisotope remaining in the object

• A method used to date ancient artifacts based on their material composition

• A technique for estimating the time of death of a living organism

• A way to measure the temperature of geological formations

Band of Stability

• The area of a graph within which all stable nuclei are found

• A region where unstable nuclei are located

• A line representing the mass number of elements

• A graph showing the decay rates of isotopes

positron emission

• A process where a nucleus emits a neutron

• A radioactive decay process that involves the emission of a positron from a nucleus

• A type of nuclear fusion reaction

• A method of electron capture in radioactive decay

Alpha decay

• Increases the number of protons and neutrons in nuclei

• Reduces the number of protons and neutrons in nuclei

• Changes the element into a different isotope without altering protons

• Releases energy without changing the atomic structure