2.  2439
Antonine Henri Becquerel)
Pierre Curie
and Marie Curie)
Po),
Ra), Th)

3. 83
,
,

4.  1.  3.
gamma)
alpha)
Electromagnetic
Wave)
2
2
2.
beta)

5. 
-
131 8.1
-238
-
131 -238 1
-238
4,500 -238
0.5 6.3
 6.3


6. 
-131
-
24
-60
-226

http://www.eei-
ku.com/images/wasinee/doct
ortool1.jpg


7. 
-238
-
239
http://vigota.blogspot.com/2011/
08/blog-post.html
http://board2.yimwhan.com/
data_user/bymics/photo/
cate_3/r2_10.jpg
-14

8. http://www.northeducation.ac.th/elearning
/ed_sc30/chap06/images/radio_activity01.
gif

9. 



10. 


