Bahan ajar Kimia powerpoint dan animasi kelas X XI XIII NuclearRadiation

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Nuclear Radiation

Natural Radioactivity

Nuclear Equations

Producing Radioactive Isotopes

Half-Life

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Subatomic Particles

• _{Protons- plus charge}

In the nucleus

• _{Neutrons- neutral}

• _{Electrons - negative charge}

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Radiation

• _{Radiation comes from the nucleus of an}

atom.

• Unstable nucleus emits a particle or energy

 alpha  beta

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Alpha Particle

Same as a helium nucleus (He)

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2 He or 

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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

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Gamma



Radiation

• Pure radiation

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Radiation Protection

• Shielding

alpha – paper, clothing beta – lab coat, gloves

gamma- lead, thick concrete • Limit time exposed

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9

Balancing Nuclear Equations

In the reactants and products

Atomic numbers must balance

and

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11

Beta decay

234

Th



234

Pa +

0

e

90 91 1

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Gamma radiation

No change in atomic or mass number

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B

11

B +

0



5 5 0

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Learning Check NR1

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Solution NR1

Write the nuclear equation for the Beta emitter Co-60.

60

Co

60

Ni +

0

e

27 28 -1

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Producing Radioactive

Isotopes

Bombardment of atoms produces radioisotopes

= 60 = 60

59Co + 1n 56Mn + 4H e

27 0 25 2

= 27 = 27

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Learning Check NR2

What radioactive isotope is produced in

the following bombardment of boron?

10

B +

4

He

? +

1

n

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Solution NR2

What radioactive isotope is produced in

the following bombardment of boron?

10

B +

4

He

13

N

+

1

n

5 2 7 0

nitrogen

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Half-Life of a Radioisotope

The time for the radiation level to fall (decay) to one-half its initial value

decay curve

8 mg 4 mg 2 mg 1 mg

initial

1

half-life ₂

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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

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Learning Check NR3

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Solution NR3

t1/2 = 13 hrs

26 hours = 2 x t1/2

Amount initial = 64mg

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Nuclear Fission

Fission

large nuclei break up

235U + 1n 139Ba + 94Kr + 3 1n +

92 0 56 36 0

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Nuclear Fusion

Fusion

small nuclei combine

2H + 3H 4He + 1n +

1 1 2 0

Occurs in the sun and other stars

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Learning Check NR4

Indicate if each of the following are

(1) Fission (2) fusion

A. Nucleus splits

B. Large amounts of energy released C. Small nuclei form larger nuclei

D. Hydrogen nuclei react

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Solution NR4

Indicate if each of the following are

(1) Fission (2) fusion

A. 1 Nucleus splits

B. 1 + 2 Large amounts of energy released C. 2 Small nuclei form larger nuclei