1) uncontrolled nuclear changes, giving off particles and rays R
2)first scientist to smash the atom R
3)smallest amount needed for a nuclear reaction to occur(2 words) C
4)high speed electron given off by radioactive elements(2 words) B
5)formulated the mass-energy equivalency E
6)material used to absorb and slow neutrons M
7)atoms with the same atomic number, different mass numbers I
8)splitting of a heavy nucleus into smaller nuclei F
9)negatively charged atomic particle E
10)time needed for half of a radioactive element to decay H
11)credited with the discovery of the radioactivity B
12)device used to control a nuclear reaction R
13) combining of lighter nuclei to form heavier ones. F
14)positively charged helium nuclei given off by radioactive elements(2words) A
15)number of protons in the nucleus of an atom(2 words) A
16)famous women physicist who discovered several radioactive elements C
17.)reactor that produces more fissionable fuel than it consumes B
18)whole number nearest the atomic weight(2words) M
19)positivly charged particle in the nucleus P
20) postive anti particle of an electron P
21)uncharged particle in the nucleus. N
Radioactive Decay Of 90/38 Sr
Directions: Get a sheet of graph paper and lable the X axis Sr90/38 grams. Lable the Y axis Time in years.Then graph the following points. Determine the half life for this material from the graph.
1) (0,16)
2) (8,30)
3) (60,4)
4) (90,2)
5) (120,1)