2. Page 63--Nuclear Equations
Nuclear equations are balanced when the sum of the atomic numbers and mass numbers are equal on both sides of the equation.

3. Nuclear Equations Nuclear equations are balanced when the sum of the atomic numbers and mass numbers are equal on both sides of the equation.
Mass numbers: = 238
238
234 4 U Th He + 92 90 2
Atomic numbers: = 92

4. Nuclear Equations Mass numbers: 234 + 4 = 238 238 234 4 U Th He + 9290 2
Atomic numbers: = 92

5. Balance the following nuclear reaction 235 U --> 231Th +
________
4 He 2

6. decrease by 4 Alpha radiation
Did the atomic MASS increase by 4 or decrease by 4?
235 U --> Th +
________
4 He 2
decrease by 4
Alpha radiation

7. Balance the following nuclear reaction 37 K --> 0e + 19 -1 ________
________
37 Ca 20

8. increase by 1 Beta radiation
Did the atomic NUMBER of K increase by 1 or decrease by 1?
37 K --> 0e +
________
37 Ca 20
increase by 1
Beta radiation

9. Balance the following nuclear reaction 235 U --> 231Th +
________
4 He 2

10. Balancing Nuclear Equations
Manipulative Activity

11. Set out your materials Make sure your board is face up (#1 on front).
Carefully empty your baggie of cards on your table
Spread them out face up

12. Solve for x and y for problem 1
Work with your group and figure out:
X = ?
Y = ?
Put your answers next to the letter on the board with your expo marker.

13. Find the card for each box
The bottom number is the atomic number.
Use your periodic table to find the element that matches each atomic number.
Place that element symbol in the box.

14. In your notebook… Record each equation on your notebook paper.
Complete each equation.
Label the equation as ALPHA, BETA, or GAMMA decay.
Repeat for each equation.
Wipe the board clean.

15. Example from words
The radioisotope lead-210 undergoes beta decay. Write a balanced equation for this reaction.

16. Example
Lead – 210  ? + beta particle
210
210 Bi e Pb + 82 83 -1

17. Example from words
The radioisotope bismuth-210 undergoes alpha decay. Write a balanced equation for this reaction.

18. Example bismuth – 210  ? + alpha particle 210 206 4 He Tl + Bi 2 8381

19. More problems worked out

20. Example #1 14 14 C N ? + 6 7
14 + ? = 14
7 + ? = 6 -1 e -1

21. Example #2
230 4 Th ? He  + + 2 90
? = 230
226 88
? = 90
226 Ra 88

22. Example #3 40 K + e ? 19 -1
40 = ? + 0 40
19 = ? + -1 20 40 Ca 20