(physics) a beta particle

a seed / a pit or stone in a fruit / a gamete (reproductive cell such as a spermatozoan or egg) / a lineage, bloodline / an origin, cause / the materials or ingredients from which something is made

(physics) a positron

physics (as an area of study)

beta

explanation

to explain

electron / (attributive) the quality of being electronic

physics, the physical aspects of a phenomenon or a system

(geology, physics) geophysics