a stream of alpha particles.
alpha particles emitted from a radioactive isotope
ionizing radiation consisting of a stream of alpha particles
alpha ray n.
A stream of alpha particles or a single high-speed alpha particle.
A stream of alpha particles.
alpha radiation [(al-fuh)]
Particles sent out by some radioactive nuclei, each particle consisting of two protons and two neutrons bound together. Alpha particles carry a positive charge. (See beta radiation and gamma radiation.)
Note: Alpha radiation, unlike gamma radiation, has low penetrating power; it can be stopped by clothing.
- Alpha ray
a stream of alpha particles. Historical Examples The alpha ray carries a positive charge of double the ionic amount. The Birth-Time of the World and Other Scientific Essays J. (John) Joly Such is a brief summary of the climax of radioactive discovery:—the birth, life and death of the alpha ray. The Birth-Time of the World […]
- Alpha receptor
a site on a cell that, upon interaction with epinephrine or norepinephrine, controls vasoconstriction, intestinal relaxation, pupil dilation, and other physiological processes.
- Alpha rhythm
a pattern of slow brain waves (alpha waves) in normal persons at rest with closed eyes, thought by some to be associated with an alert but daydreaming mind. noun (physiol) the normal bursts of electrical activity from the cerebral cortex of a drowsy or inactive person, occurring at a frequency of 8 to 12 hertz […]
- Alpha-stannic acid
See under . any of the series of acids usually occurring as amorphous powders and varying in composition from H 2 SnO 3 (alpha-stannic acid) to H 4 SnO 4 .