Isotope

Isotopic Mass

amu

% Abundance

T_1/2

T_1/2

Units

Mass Excess

KeV

Binding Energy

Per Nucleon

KeV

Decay

Mode

Branching

Ratio

²²⁵Np

225.033914 (77)

3

ms

31,591 (72)

7,607.5 (3.2)

A

100

²²⁶Np

226.035145 (95)

35

ms

32,738 (88)

7,605 (0)

A

100

²²⁷Np

227.034957 (78)

510

ms

32,562 (73)

7,607.4 (3.2)

A~100

²²⁸Np

228.03618 (21)

61.4

s

33,700 (200)

7,604 (1)

EC

60 7

²²⁹Np

229.036264 (93)

4

m

33,780 (87)

7,606.1 (3.8)

A>50

²³⁰Np

230.037828 (55)

4.6

m

35,236 (51)

7,601.8 (2.2)

B+ LE 97

²³¹Np

231.038245 (54)

48.8

m

35,625 (51)

7,602.1 (2.2)

B+

98 1

²³²Np

232.04011 (11)

14.7

m

37,360 (100)

7,597 (0)

B+~100

²³³Np

233.040741 (55)

36.2

m

37,950 (51)

7,596.2 (2.2)

B+~100

²³⁴Np

234.0428950 (91)

4.4

d

39,956.5 (8.5)

7,589.63 (3.6)

B+

100

²³⁵Np

235.0440633 (21)

396.1

d

41,044.7 (2)

7,587.049 (8)

EC~100

²³⁶Np

236.046570 (54)

154

ky

43,379 (50)

7,579.2 (2.1)

EC

87.3 5

²³⁷Np

237.0481734 (20)

2.144

My

44,873.3 (1.8)

7,574.982 (8)

A

100

²³⁸Np

238.0509464 (20)

2.117

d

47,456.3 (1.8)

7,566.214 (8)

B-

100

²³⁹Np

239.0529390 (22)

2.356

d

49,312.4 (2.1)

7,560.561 (9)

B-

100

²⁴⁰Np

240.056162 (16)

61.9

m

52,315 (15)

7,550.18 (6.3)

B-

100

²⁴¹Np

241.058252 (76)

13.9

m

54,262 (71)

7,544.3 (2.9)

B-

100

²⁴²Np

242.06164 (21)

2.2

m

57,420 (200)

7,533.4 (8.3)

B-

100

²⁴³Np

243.064279 (34)

1.85

m

59,875 (32)

7,525 (0)

B-

100

²⁴⁴Np

244.06785 (32)

2.29

m

63,200 (300)

7,514 (1)

B-

^236mNp

236.046570 (54)

22.5

h

43,379 (50)

7,579.2 (2.1)

EC

52 1

^238mNp

238.0509464 (20)

112

ns

47,456.3 (1.8)

7,566.214 (8)

SF~100

^240mNp

240.056162 (16)

7.22

m

52,315 (15)

7,550.18 (6.3)

B-~100

^242mNp

242.06164 (21)

5.5

m

57,420 (200)

7,533.4 (8.3)

B-

100

^229mNp

229.036264 (93)

33,780 (87)

7,606.1 (3.8)

0

^230mNp

230.037828 (55)

35,236 (51)

7,601.8 (2.2)

0

^231mNp

231.038245 (54)

35,625 (51)

7,602.1 (2.2)

0

^233mNp

233.040741 (55)

37,950 (51)

7,596.2 (2.2)

0

^236m1Np

236.046570 (54)

43,379 (50)

7,579.2 (2.1)

0

^243mNp

243.064279 (34)

59,875 (32)

7,525 (0)

0