the quality in a sound of being deep, full, and reverberating

the resonance of his voice

the reinforcement or prolongation of sound by reflection from a surface or by the synchronous vibration of a neighbouring object

the condition in which an electric circuit or device produces the largest possible response to an applied oscillating signal

the occurrence of a simple ratio between the periods of revolution of two bodies about a single primary

the property of having a molecular structure which cannot adequately be represented by a single structural formula but is a composite of two or more structures of higher energy

a short-lived subatomic particle that is an excited state of a more stable particle