You can search for things like...

Curium
Space Group Number of Copernicium
Rf (Symbol of Rutherfordium)
34 (Atomic Number of Selenium)
Neel Point of Niobium in °F

Np

Neptunium

25 known isotopes (0 stable, 25 radioactive)

Show stable only

²¹⁹Np

Mass

219.031602 u

Abundance

—

Half-life

0.15 milliseconds

Spin/Parity

(9/2-)

Decay Mode(s)

α (100%)

²²⁰Np

Mass

220.032716 u

Abundance

—

Half-life

25 microseconds

Spin/Parity

—

Decay Mode(s)

α (100%)

²²²Np

Mass

222.033575 u

Abundance

—

Half-life

0.38 microseconds

Spin/Parity

—

Decay Mode(s)

α (100%)

²²³Np

Mass

223.032913 u

Abundance

—

Half-life

2.2 microseconds

Spin/Parity

(9/2-)

Decay Mode(s)

α (100%)

²²⁴Np

Mass

224.034388 u

Abundance

—

Half-life

38 microseconds

Spin/Parity

—

Decay Mode(s)

α (100%)

²²⁵Np

Mass

225.033943 u

Abundance

—

Half-life

3.6 milliseconds

Spin/Parity

—

Decay Mode(s)

α (100%)

²²⁶Np

Mass

226.035230 u

Abundance

—

Half-life

35 milliseconds

Spin/Parity

—

Decay Mode(s)

α (100%)

²²⁷Np

Mass

227.034975 u

Abundance

—

Half-life

0.51 seconds

Spin/Parity

—

Decay Mode(s)

α (100%)

²²⁸Np

Mass

228.036313 u

Abundance

—

Half-life

61.4 seconds

Spin/Parity

—

Decay Mode(s)

Electron capture (60%), α (40%)

²²⁹Np

Mass

229.036287 u

Abundance

—

Half-life

4.0 m

Spin/Parity

—

Decay Mode(s)

α (68%), Electron capture (32%)

²³⁰Np

Mass

230.037828 u

Abundance

—

Half-life

4.6 m

Spin/Parity

—

Decay Mode(s)

EC/β⁺ (97%), α (3%)

²³¹Np

Mass

231.038244 u

Abundance

—

Half-life

48.8 m

Spin/Parity

(5/2-)

Decay Mode(s)

EC/β⁺ (98%), α (2%)

²³²Np

Mass

232.040107 u

Abundance

—

Half-life

14.7 m

Spin/Parity

(4+)

Decay Mode(s)

EC/β⁺ (100%), α (0.0002%)

²³³Np

Mass

233.040739 u

Abundance

—

Half-life

36.2 m

Spin/Parity

(5/2+)

Decay Mode(s)

Electron capture (100%), α (0.0007%)

²³⁴Np

Mass

234.042893 u

Abundance

—

Half-life

4.4 d

Spin/Parity

(0+)

Decay Mode(s)

EC/β⁺ (100%)

²³⁵Np

Mass

235.044062 u

Abundance

—

Half-life

396.1 d

Spin/Parity

5/2+

Decay Mode(s)

Electron capture (99.9974%), α (0.0026%)

²³⁶Np

Mass

236.046568 u

Abundance

—

Half-life

1.55E+5 years

Spin/Parity

6(-)

Decay Mode(s)

Electron capture (87.8%), β⁻ (12%), α (0.16%)

²³⁷Np

Mass

237.048172 u

Abundance

—

Half-life

2.144E+6 years

Spin/Parity

5/2+

Decay Mode(s)

α (100%), Spontaneous fission (2e-10%)

²³⁸Np

Mass

238.050945 u

Abundance

—

Half-life

2.099 d

Spin/Parity

2+

Decay Mode(s)

β⁻ (100%)

²³⁹Np

Mass

239.052938 u

Abundance

—

Half-life

2.356 d

Spin/Parity

5/2+

Decay Mode(s)

β⁻ (100%)

²⁴⁰Np

Mass

240.056164 u

Abundance

—

Half-life

61.9 m

Spin/Parity

(5+)

Decay Mode(s)

β⁻ (100%)

²⁴¹Np

Mass

241.058310 u

Abundance

—

Half-life

13.9 m

Spin/Parity

5/2+

Decay Mode(s)

β⁻ (100%)

²⁴²Np

Mass

242.061640 u

Abundance

—

Half-life

2.2 m

Spin/Parity

(1+)

Decay Mode(s)

β⁻ (100%)

²⁴³Np

Mass

243.064204 u

Abundance

—

Half-life

1.85 m

Spin/Parity

(5/2)

Decay Mode(s)

β⁻ (100%)

²⁴⁴Np

Mass

244.067891 u

Abundance

—

Half-life

2.29 m

Spin/Parity

(7-)

Decay Mode(s)

β⁻ (100%)

Decay mode abbreviations:

β⁻ = Beta minus decay, β⁺ = Beta plus decay, EC = Electron capture, α = Alpha decay

n = Neutron emission, p = Proton emission, SF = Spontaneous fission, IT = Isomeric transition

Conversions Print

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

1

2

3

4

5

6

7

N

Sy

Name

Atomic Mass

Series

Metals

Nonmetals