408
Nuclear Chemistry
would be left in the atmosphere after 1000 yrs° (Assume that none of it
settles out )
8 If you seal a 100 g sample of very pure uranium in a container for safekeeping,
and if in the distant future a scientist dissolves it and finds it to contain
0 800 g -'sliPb, how many years have elapsed since you sealed the sample"
7
(Lead is the stable endproduct of the radioactive decay of uranium)
9 Willard Libby and colleagues have found that a very small amount of the CO 2
in the air is radioactive, as a result of continuous bombardment of nitrogen in
the upper atmosphere by neutrons of cosmic origin This radioactive 'JC is
uniformly distributed among all forms of carbon that are in equilibrium with the
atmosphere, and it is found to show 15 3 cpm/gram of carbon All plants use
CO 2 for growth, and while living are in equilibrium with the atmosphere When
plants die, they no longer remain in equilibrium with the air, and the carbon
slowly loses its activity Cyprus wood from the ancient Egyptian tomb of
Sneferu at Meydum has an activity of 6 88 cpm/g of carbon Estimate the age of
this wood (and presumably the age of the tomb)
10 A 0 500 g sample of-jgRa is sealed into a very thin-walled tube, so that the a
particles emitted from the radium and its decay products can penetrate and be
collected in an evacuated volume of 25 0 ml What helium pressure at 20 0°C
will build up in 100 yrs
7 (Five a particles are produced as radium disintegrates
to a stable isotope of lead )
11 Solve Problems 1, 2, 3, and 4 on p 247
PROBLEMS B
12 Write nuclear equations to show the disintegration of the last six radioactive
isotopes listed in Table 26-1
13 The following isotopes are artificially radioactive They emit the particles
shown in parentheses Write nuclear equations to show the disintegration of
these isotopes
(a) igNe (_fe)
(d) ! 7
4 Rb (_fe)
(b) l^Ar(_?e)
(e)
13
7 N (°e)
(c) UK (?e)
14 Bombardment reactions often are summarized in a terse form, as explained in
Problem 3 Give the complete balanced nuclear equation for each of the
following transmutation bombardments
(a) »Be(p d)
(d) l 8 °Ar(n,y)
(b) '10(d,a)
(e) i 2
3 Mg(a,p)
(c) i 3
7 Al(n,a)
15 (a) Calculate the energy liberated per mole of He when the following reaction
takes place
?H + iH -* |He + Jn
Nuclear Chemistry
would be left in the atmosphere after 1000 yrs° (Assume that none of it
settles out )
8 If you seal a 100 g sample of very pure uranium in a container for safekeeping,
and if in the distant future a scientist dissolves it and finds it to contain
0 800 g -'sliPb, how many years have elapsed since you sealed the sample"
7
(Lead is the stable endproduct of the radioactive decay of uranium)
9 Willard Libby and colleagues have found that a very small amount of the CO 2
in the air is radioactive, as a result of continuous bombardment of nitrogen in
the upper atmosphere by neutrons of cosmic origin This radioactive 'JC is
uniformly distributed among all forms of carbon that are in equilibrium with the
atmosphere, and it is found to show 15 3 cpm/gram of carbon All plants use
CO 2 for growth, and while living are in equilibrium with the atmosphere When
plants die, they no longer remain in equilibrium with the air, and the carbon
slowly loses its activity Cyprus wood from the ancient Egyptian tomb of
Sneferu at Meydum has an activity of 6 88 cpm/g of carbon Estimate the age of
this wood (and presumably the age of the tomb)
10 A 0 500 g sample of-jgRa is sealed into a very thin-walled tube, so that the a
particles emitted from the radium and its decay products can penetrate and be
collected in an evacuated volume of 25 0 ml What helium pressure at 20 0°C
will build up in 100 yrs
7 (Five a particles are produced as radium disintegrates
to a stable isotope of lead )
11 Solve Problems 1, 2, 3, and 4 on p 247
PROBLEMS B
12 Write nuclear equations to show the disintegration of the last six radioactive
isotopes listed in Table 26-1
13 The following isotopes are artificially radioactive They emit the particles
shown in parentheses Write nuclear equations to show the disintegration of
these isotopes
(a) igNe (_fe)
(d) ! 7
4 Rb (_fe)
(b) l^Ar(_?e)
(e)
13
7 N (°e)
(c) UK (?e)
14 Bombardment reactions often are summarized in a terse form, as explained in
Problem 3 Give the complete balanced nuclear equation for each of the
following transmutation bombardments
(a) »Be(p d)
(d) l 8 °Ar(n,y)
(b) '10(d,a)
(e) i 2
3 Mg(a,p)
(c) i 3
7 Al(n,a)
15 (a) Calculate the energy liberated per mole of He when the following reaction
takes place
?H + iH -* |He + Jn