1. Module 7

1.18. Module Glossary

Glossary

Module 7—Investigating the Nature of the Atom

 

Module Glossary

 

absorption spectrum: a pattern of dark lines produced when light passes through a gas at low pressure

 

cathode ray: a free electron emitted by a negative electrode in a low-pressure environment

 

elementary unit of charge: the charge of an electron or a proton, 1.60 × 10–19 C

 

emission spectrum: a pattern of bright lines produced by a hot gas at low pressure

 

energy level: a discrete and quantized amount of energy

 

spectroscopy: the study of the light emitted and absorbed by different materials

 

stationary state: a stable state with a fixed energy level