Rutherfordium
Isotopes
Table:
Isotope half-lives and discovery years

Isotope

Half-life
[7]
Decay
mode[7]
Discovery
year
Reaction

253Rf
48 μs
α, SF
1994
204Pb(50Ti,n)[17]

254Rf
23 μs
SF
1994
206Pb(50Ti,2n)[17]

255Rf
2.3 s
ε?, α, SF
1974
207Pb(50Ti,2n)[18]

256Rf
6.4 ms
α, SF
1974
208Pb(50Ti,2n)[18]

257Rf
4.7 s
ε, α, SF
1969
249Cf(12C,4n)[12]

257mRf
4.1 s
ε, α, SF
1969
249Cf(12C,4n)[12]

258Rf
14.7 ms
α, SF
1969
249Cf(13C,4n)[12]

259Rf
3.2 s
α, SF
1969
249Cf(13C,3n)[12]

259mRf
2.5 s
ε
1969
249Cf(13C,3n)[12]

260Rf
21 ms
α, SF
1969
248Cm(16O,4n)[11]

261Rf
78 s
α, SF
1970
248Cm(18O,5n)[19]

261mRf
4 s
ε, α, SF
2001
244Pu(22Ne,5n)[20]

262Rf
2.3 s
α, SF
1996
244Pu(22Ne,4n)[21]

263Rf
15 min
α, SF
1999
263Db(
e−
,
ν
e)[22]

263mRf ?
8 s
α, SF
1999
263Db(
e−
,
ν
e)[22]

265Rf
1.1 min[8]
SF
2010
269Sg(—,α)[23]

266Rf
23 s?
SF
2007?
266Db(
e−
,
ν
e)?[24][25]

267Rf
1.3 h
SF
2004
271Sg(—,α)[26]

268Rf
1.4 s?
SF
2004?
268Db(
e−
,
ν
e)?[25][27]

270Rf
20 ms?[28]
SF
2010?
270Db(
e−
,
ν
e)?[29]

Referring to the table titled Rutherfordium, section Isotopes, answer the following question with a short sentence: Which isotope has been reported? Respond with the correct answer in JSON format as {"answer": "YOUR ANSWER"}.

answer: Sixteen different isotopes have been reported with atomic masses from 253 to 270 (with the exceptions of 264 and 269).