Bahan ajar Kimia powerpoint dan animasi kelas X XI XIII NuclearRadiation
Nuclear Radiation
Natural Radioactivity
Nuclear Equations
Producing Radioactive Isotopes
Half-Life
Nuclear Fission and Fusion
1
Subatomic Particles
• Protons- plus charge
In the nucleus
• Neutrons- neutral
• Electrons - negative charge
Outside the nucleus
2
Radiation
• Radiation comes from the nucleus of an
atom.
• Unstable nucleus emits a particle or energy
alpha
beta
gamma
3
Alpha Particle
Same as a helium nucleus
(He)
4
2
He
or
Two protons
Two neutrons
4
Beta Particle
An electron emitted from the nucleus
0
e or
1
A neutron in the nucleus breaks down
1 1
0
n
H
+
e
0
1
-1
5
Gamma Radiation
• Pure radiation
• Like an X-ray but comes from the nucleus
6
Radiation Protection
• Shielding
alpha – paper, clothing
beta – lab coat, gloves
gamma- lead, thick concrete
• Limit time exposed
• Keep distance from source
7
Radiation Protection
8
Balancing Nuclear Equations
In the reactants and products
Atomic numbers must balance
and
Mass numbers must balance
9
Alpha decay
10
Beta decay
234
90
Th
Pa
234
91
+ 0e
1
beta particle
11
Gamma radiation
No change in atomic or mass number
B
11
5
B +
11
5
0
0
boron atom in a
high-energy state
12
Learning Check NR1
Write the nuclear equation for the beta
emitter Co-60.
13
Solution NR1
Write the nuclear equation for the
Beta emitter Co-60.
Co
60
27
Ni +
60
28
0
e
-1
14
Producing Radioactive
Isotopes
Bombardment of atoms produces
radioisotopes
= 60
59
Co
= 60
+ 1n
27
0
= 27
cobalt
atom
Mn +
56
25
He
4
2
= 27
neutron
manganese alpha
radioisotope particle
15
Learning Check NR2
What radioactive isotope is produced in
the following bombardment of boron?
10
5
B
+ 4He
2
? +
n
1
0
16
Solution NR2
What radioactive isotope is produced in
the following bombardment of boron?
10
5
B
+ 4He
2
13
7
N
+
n
1
0
nitrogen
radioisotope
17
Half-Life of a Radioisotope
The time for the radiation level to fall
(decay) to one-half its initial value
decay curve
initial
1
half-life
8 mg
4 mg
2
2 mg
3
1 mg
18
Examples of Half-Life
Isotope
Half life
C-152.4 sec
Ra-224 3.6 days
Ra-223 12 days
I-125
60 days
C-145700 years
U-235
710 000 000 years
19
Learning Check NR3
The half life of I-123 is 13 hr. How much
of a 64 mg sample of I-123 is left after
26 hours?
20
Solution NR3
t1/2
=
13 hrs
26 hours
=
2 x t1/2
Amount initial
=
64mg
Amount remaining = 64 mg x ½ x ½
= 16 mg
21
Nuclear Fission
Fission
large nuclei break up
235
U
92
+ 1n
0
139
56
Ba + 94Kr + 3 1n +
36
Energy
0
22
Fission
23
Nuclear Fusion
Fusion
small nuclei combine
2
H
1
+
3
1
H
4
2
He
+ 1n +
Energy
0
Occurs in the sun and other stars
24
Learning Check NR4
Indicate if each of the following are
(1) Fission
(2) fusion
A.
B.
C.
D.
Nucleus splits
Large amounts of energy released
Small nuclei form larger nuclei
Hydrogen nuclei react
Energy
25
Solution NR4
Indicate if each of the following are
(1) Fission
(2) fusion
A.
B.
C.
D.
1
1+2
2
2
Nucleus splits
Large amounts of energy released
Small nuclei form larger nuclei
Hydrogen nuclei react
26
Natural Radioactivity
Nuclear Equations
Producing Radioactive Isotopes
Half-Life
Nuclear Fission and Fusion
1
Subatomic Particles
• Protons- plus charge
In the nucleus
• Neutrons- neutral
• Electrons - negative charge
Outside the nucleus
2
Radiation
• Radiation comes from the nucleus of an
atom.
• Unstable nucleus emits a particle or energy
alpha
beta
gamma
3
Alpha Particle
Same as a helium nucleus
(He)
4
2
He
or
Two protons
Two neutrons
4
Beta Particle
An electron emitted from the nucleus
0
e or
1
A neutron in the nucleus breaks down
1 1
0
n
H
+
e
0
1
-1
5
Gamma Radiation
• Pure radiation
• Like an X-ray but comes from the nucleus
6
Radiation Protection
• Shielding
alpha – paper, clothing
beta – lab coat, gloves
gamma- lead, thick concrete
• Limit time exposed
• Keep distance from source
7
Radiation Protection
8
Balancing Nuclear Equations
In the reactants and products
Atomic numbers must balance
and
Mass numbers must balance
9
Alpha decay
10
Beta decay
234
90
Th
Pa
234
91
+ 0e
1
beta particle
11
Gamma radiation
No change in atomic or mass number
B
11
5
B +
11
5
0
0
boron atom in a
high-energy state
12
Learning Check NR1
Write the nuclear equation for the beta
emitter Co-60.
13
Solution NR1
Write the nuclear equation for the
Beta emitter Co-60.
Co
60
27
Ni +
60
28
0
e
-1
14
Producing Radioactive
Isotopes
Bombardment of atoms produces
radioisotopes
= 60
59
Co
= 60
+ 1n
27
0
= 27
cobalt
atom
Mn +
56
25
He
4
2
= 27
neutron
manganese alpha
radioisotope particle
15
Learning Check NR2
What radioactive isotope is produced in
the following bombardment of boron?
10
5
B
+ 4He
2
? +
n
1
0
16
Solution NR2
What radioactive isotope is produced in
the following bombardment of boron?
10
5
B
+ 4He
2
13
7
N
+
n
1
0
nitrogen
radioisotope
17
Half-Life of a Radioisotope
The time for the radiation level to fall
(decay) to one-half its initial value
decay curve
initial
1
half-life
8 mg
4 mg
2
2 mg
3
1 mg
18
Examples of Half-Life
Isotope
Half life
C-152.4 sec
Ra-224 3.6 days
Ra-223 12 days
I-125
60 days
C-145700 years
U-235
710 000 000 years
19
Learning Check NR3
The half life of I-123 is 13 hr. How much
of a 64 mg sample of I-123 is left after
26 hours?
20
Solution NR3
t1/2
=
13 hrs
26 hours
=
2 x t1/2
Amount initial
=
64mg
Amount remaining = 64 mg x ½ x ½
= 16 mg
21
Nuclear Fission
Fission
large nuclei break up
235
U
92
+ 1n
0
139
56
Ba + 94Kr + 3 1n +
36
Energy
0
22
Fission
23
Nuclear Fusion
Fusion
small nuclei combine
2
H
1
+
3
1
H
4
2
He
+ 1n +
Energy
0
Occurs in the sun and other stars
24
Learning Check NR4
Indicate if each of the following are
(1) Fission
(2) fusion
A.
B.
C.
D.
Nucleus splits
Large amounts of energy released
Small nuclei form larger nuclei
Hydrogen nuclei react
Energy
25
Solution NR4
Indicate if each of the following are
(1) Fission
(2) fusion
A.
B.
C.
D.
1
1+2
2
2
Nucleus splits
Large amounts of energy released
Small nuclei form larger nuclei
Hydrogen nuclei react
26