Z

N

No. of n-n Interactions

No. of p-p Interactions

No. of n-p Interactions

S (n-n) + (p-p)

- 2.5 (n-p)

0

27

351

0

0

+351

1

26

325

0

26

+260

2

25

300

1

50

+176

3

24

276

3

72

+96

4

23

253

6

92

+29

5

22

231

10

110

-34

6

21

210

15

126

-90

7

20

190

21

140

-139

8

19

171

28

152

-181

9

18

153

36

162

-216

10

17

136

45

170

-244

11

16

120

55

176

-265

12

15

105

66

180

-279

13

14

91

78

182

-286

14

13

78

91

182

-286

15

12

66

105

180

-279

16

11

55

120

176

-265

17

10

45

136

170

-244

18

9

36

153

162

-216

19

8

28

171

152

-181

20

7

21

190

140

-139

21

6

15

210

126

-90

22

5

10

231

110

-34

23

4

6

253

92

+29

24

3

3

276

72

+96

25

2

1

300

50

+176

26

1

0

325

26

+260

27

0

0

351

0

+351