Chem Unit 2: Atoms and Nuclear Chemistry
Gamma rays
High energy electromagnetic waves emitted from a nucleus as it changes from an excited state to a ground energy state
Positron
A particle that has the same mass as an electron but has a positive charge, and is emitted from the nucleus during some kinds of radioactive decay.
Fission
The breaking apart of large radioactive atoms into smaller atoms releasing large amounts of energy
Electrostatic force
Protons repel each other in the nucleus due to…
Mass number
The total number of protons and neutrons in the nucleus of an isotope
Beta
A particle that is an electron emitted from the nucleus during some kinds of radioactive decay
Nuclide
Refers to the nucleus of a specific isotope
Nuclear stability
Determined by the ratio of protons to neutrons in the nuclide for an isotope
Nuclear binding energy
The energy released when a nucleus is formed from nucleons
Radioisotopes
Radioactivity occurs in isotopes with unstable nuclides also known as
Mass defect
The difference between the mass of an atom and the sum of the masses of its protons, neutrons, and electrons
Atomic Number
The number of protons in the nucleus of each atom of that atom
Particles
The mass of one mole per substance with units of g/mol
Atomic Mass Unit
Exactly 1/12 the mass of a carbon-12 atom
Nucleons
Refers to both protons and the the neutrons in the nucleus
Alpha
A particle with two protons and two neutrons bound together and is emitted from the nucleus during some kinds of radioactive decay; the most massive type of radiation
Half life
The time required for half the atoms of a radioactive nuclide to decay
Avogadro’s number
6.02 x 10^23 representative particles
Nuclear radiation
Particles or electromagnetic radiation emitted from the nucleus during radioactive decay
REM
Unit that measures nuclear radiation exposure to humans
Isotope
An atom of the same element that has a different mass due to its different number of neutrons
Roentgen
Unit that measures nuclear radiation exposure to the environment
Nuclear decay
The spontaneous disintergration of a nucleus into a slightly lighter nucleus; accompanied by emission of particles, electromagnetic radiation, or both
Mole
The SI base unit for amount of substance
Fusion
The combining of smaller atoms into larger atoms releasing large amounts of energy; occurs at very high tmeperatures
Nuclear Force
Protons close to one another attract each other due to…
Atom
The smallest particle of an element that retains the chemical properties of that element
Average Atomic Mass
The weighted average of the atomic masses of the naturally occurring isotopes of an element
Nuclear Chemistry
The branch of chemistry dealing with changes in or transformations of the atomic nucleus
Radioactivity
The process by which nuclei emit particles and rays; named by Madame Curie