http://www.ck12.org Chapter 26. Glossary
26.8 H
half-life
Length of time it takes for half of a given amount of a radioisotope to decay.
halogen
Nonmetal in group 17 of the periodic table that has seven valence electrons and is highly reactive.
heat
Transfer of thermal energy between objects that have different temperatures.
hertz (Hz)
SI unit of wave frequency, where 1 hertz equals 1 wave passing a fixed point per second.
hydrocarbon
Carbon-based compound that contains only carbon and hydrogen.
hydrogen bond
Weak bond that forms between a slightly positive hydrogen atom in one molecule and a slightly negative atom
in another molecule.
hypothesis
Potential answer to a question that can be tested by gathering information.