Nuclear physics (1 Viewer)

[Bdogz]

what determines if a substance undergoes alpha or beta decay?

 

[AlexJB]

Put simply, alpha decay occurs when there is too many protons and beta decay occurs when there is too many neutrons.

 

[Bdogz]

Put simply, alpha decay occurs when there is too many protons and beta decay occurs when there is too many neutrons.

oh k n does beta decay usually follow alpha decay and vice versa?

 

[darkchild69]

Not necessarily. For example U-234 undergoes alpha decay to form Th-230 which then undergoes alpha decay to form Ra-226, alpha again to form Rn-222, alpha again to form Po-218 and alpha AGAIN to form Pb-214, then beta to form Bi-214. It all depends on the stability of the atom and the Neutronroton ratio

Alpha emission principally occurs whit nuclei which are too large to be stable. When a nucleus emits an alpha particle, it's N and Z values each decrease by two and A decreases by 4, moving it closer to stable territory on the Segre chart. The segre chart shows the region of stability for different nuclides.

Beta decay, you have three types. Beta minus decay, Beta plus decay and electron capture.
Beta-minus decay usually occurs with nuclides for which the Neutron to Proton ratio is too large.
Beta-plus decay usually occurs for when the N/Z ratio is too small for stability and can emit a positron (antiparticle of the electron)
Electron capture occurs when an orbital electron (usually the K shell) combines with a proton in the nucleus to produce a neutron and a neutrino. The neutron remains in the nucleus and the neutrino is emitted. This occurs when the nuclide is unstable, but for which Beta plus decay is not energetically possible.

I dont think u need to know about electron capture for HSC, but it's interesting nonetheless

Put simply, alpha decay occurs when there is too many protons and beta decay occurs when there is too many neutrons.

True only for Beta-minus decay!