Scandium-45

Main isotopes of scandium

Isotope			Decay
	abundance	half-life	mode	energy (MeV)	product
^44m2Sc	syn	58.61 h	IT	0.2709	⁴⁴Sc
			γ	1.0, 1.1, 1.1	⁴⁴Sc
			ε	–	⁴⁴Ca
⁴⁵Sc	100%	is stable with 24 neutrons
⁴⁶Sc	syn	83.79 d	β⁻	0.3569	⁴⁶Ti
⁴⁶Sc	syn	83.79 d	γ	0.889, 1.120	–
⁴⁷Sc	syn	80.38 d	β⁻	0.44, 0.60	⁴⁷Ti
⁴⁷Sc	syn	80.38 d	γ	0.159	–
⁴⁸Sc	syn	43.67 h	β⁻	0.661	⁴⁸Ti
⁴⁸Sc	syn	43.67 h	γ	0.9, 1.3, 1.0	–

Standard atomic weight (A_r)

7001449559080000000♠44.955908(5)

Naturally occurring scandium (₂₁Sc) is composed of one stable isotope ⁴⁵Sc. Twenty-four radioisotopes have been characterized with the most stable being ⁴⁶Sc with a half-life of 83.8 days, ⁴⁷Sc with a half-life of 3.35 days, and ⁴⁸Sc with a half-life of 43.7 hours and Sc-44 with a half-life of 3.97 hours. All of the remaining radioactive isotopes have half-lives that are less than four hours, and the majority of these have half-lives that are less than two minutes, the least stable being ³⁹Sc with a half-life shorter than 300 nanoseconds. The half-lives for isotopes with mass numbers less than 39 is unknown. This element also has 10 meta states with the most stable being ^44m2Sc (t_1/2 58.6 h).

The isotopes of scandium range in atomic weight from 36 u (³⁶Sc) to 60 u (⁶⁰Sc). The primary decay mode at masses lower than the only stable isotope, ⁴⁵Sc, is Beta-plus or electron capture, and the primary mode at masses above it is beta-minus. The primary decay products at atomic weights below ⁴⁵Sc are calcium isotopes and the primary products from higher atomic weights are titanium isotopes.

...
Wikipedia