Problems A
407
and dr = 10.0 yrs (an infinitesimal period of time in this problem). Consequently,
= 1.54 x 1 0~
9 g of
2 HU that disintegrates
PROBLEMS
1. Write nuclear equations to show the disintegration of the first six radioactive
isotopes listed in Table 26-1.
2. The following isotopes are artificially radioactive. They emit the particles
shown in parentheses. Write nuclear equations to show the disintegration of
these isotopes.
(a)
2
4
7 Si (?e)
(d)
2
,
4
Na (_fe)
(b)
2
3
8 A1 (_?e)
(e) 'IF (?e)
(c)
3. Bombardment reactions are often summarized in a terse form, such as
^Be(a,n). This means that the target (^Be) is bombarded by a particles GHe),
and that neutrons (Jn) are produced. By the rules for balancing nuclear equations, we know that '1C also is produced. Give the complete balanced nuclear
equation for each of the following transmutation bombardments (p stands for
proton, and d stands for deuteron in this notation).
(a)
14
7 N(n,p)
(d)
14
7 N(a,p)
(b)
2 fMg(N,a)
(e) IiCu(p,n)
(c) l?Co(d,p)
4. (a) Calculate the energy liberated per mole of lithium when the following
reaction takes place:
IU + 1H -> 2
4 He
The actual mole weights involved are JLi = 7.01818 g; !H = 1.00813 g;
|He = 4.00386 g.
(b) How many tons of carbon would have to be burned to give as much energy
as 100 g of JLi consumed by this reaction? (Carbon gives 94. 1 kcal/mole
when burned to CO 2 .)
5. The halogen astatine can be obtained only by artificial methods through bombardment. It has been found useful for the treatment of certain types of cancer of the thyroid gland, for it migrates to this gland just as iodine does. If a
sample containing 0.1 mg of
2 ssAt is given to a person at 9 A.M. one morning,
how much will remain in the body at 9 A.M. the following morning?
6. A purified sample of a radioactive compound is found to have 1365 cpm at 10
A.M., but only 832 cpm at 1 P.M. the same day. What is the half-life of
this sample?
7. If in the explosion of one atom bomb 50.0 g of "IPu were scattered about in
the atmosphere before it had a chance to undergo nuclear fission, how much
407
and dr = 10.0 yrs (an infinitesimal period of time in this problem). Consequently,
= 1.54 x 1 0~
9 g of
2 HU that disintegrates
PROBLEMS
1. Write nuclear equations to show the disintegration of the first six radioactive
isotopes listed in Table 26-1.
2. The following isotopes are artificially radioactive. They emit the particles
shown in parentheses. Write nuclear equations to show the disintegration of
these isotopes.
(a)
2
4
7 Si (?e)
(d)
2
,
4
Na (_fe)
(b)
2
3
8 A1 (_?e)
(e) 'IF (?e)
(c)
3. Bombardment reactions are often summarized in a terse form, such as
^Be(a,n). This means that the target (^Be) is bombarded by a particles GHe),
and that neutrons (Jn) are produced. By the rules for balancing nuclear equations, we know that '1C also is produced. Give the complete balanced nuclear
equation for each of the following transmutation bombardments (p stands for
proton, and d stands for deuteron in this notation).
(a)
14
7 N(n,p)
(d)
14
7 N(a,p)
(b)
2 fMg(N,a)
(e) IiCu(p,n)
(c) l?Co(d,p)
4. (a) Calculate the energy liberated per mole of lithium when the following
reaction takes place:
IU + 1H -> 2
4 He
The actual mole weights involved are JLi = 7.01818 g; !H = 1.00813 g;
|He = 4.00386 g.
(b) How many tons of carbon would have to be burned to give as much energy
as 100 g of JLi consumed by this reaction? (Carbon gives 94. 1 kcal/mole
when burned to CO 2 .)
5. The halogen astatine can be obtained only by artificial methods through bombardment. It has been found useful for the treatment of certain types of cancer of the thyroid gland, for it migrates to this gland just as iodine does. If a
sample containing 0.1 mg of
2 ssAt is given to a person at 9 A.M. one morning,
how much will remain in the body at 9 A.M. the following morning?
6. A purified sample of a radioactive compound is found to have 1365 cpm at 10
A.M., but only 832 cpm at 1 P.M. the same day. What is the half-life of
this sample?
7. If in the explosion of one atom bomb 50.0 g of "IPu were scattered about in
the atmosphere before it had a chance to undergo nuclear fission, how much