Refers to a result that is statistically unlikely to have occurred by chance alone.
Statistically significant
Number of protons in the atomic nucleus, determines the element
Atomic Number
Electrical property; opposite charges attract and like charges repel.
Charge
Negatively charged subatomic particle
Electron
A pure substance that consist only of atoms with the same number of protons.
Element
Forms of an element that differ in the number of neutrons their atoms carry.
Isotopes
Of an isotope, the total number of protons and neutrons in the atomic nucleus.
Mass number
Uncharged subatomic particle in the atomic nucleus
Neutron
Core of an atom; occupied by protons and neutrons.
Nucleus
Positively charged subatomic particle that cocurs in the nucleus of all atoms
Proton
Process by which atoms of a radioisotope emit energy and subatomic particles when their nucleus spontatneously breaks up
Radioactive decay
Isotope with an unstable nucleus.
Radioisotope
Atom with an unpaired electron.
Free radical
Atom or molecule that carries a net charge.
Ion
Model of electron distribution in an atom.
Shell model
A substance that can be traced via its detectable component.
Tracer
An attractive force that arises between two atoms when their electrons interact. Links atoms into molecules.
Chemical bond
Molecule that has atoms of more than one element.
Compound
Type of chemical bond in which two atoms share a pair of electrons.
Covalent bond
Type of chemical bond in which a strong mutual attraction links ions of opposite charge.
Ionic bond
Any separation of charge into distinct positive and negative regions.
Polarity
Propery of a substance that arises from the tendency of its molecultes to resist separating from one another.
Cohesion
Amount of solute per unit volume of solution.
Concentration
Transition of a liquid to a vapor.
Evaporation
Attraction between covalently bonded hydrogen atom and another atom taking part in a separate covalent bond.
Hydrogen bond