1. Chemistry
Nuclear Chemistry

2. Basics of the Atom
Location in
the Atom
Particle
Charge
Mass
proton 1+
in nucleus
~1 u
neutron
in nucleus
~1 u
electron 1–
orbiting nucleus
~1/2000 u
a.m.u. (u): unit used to measure mass of atoms

3. To find net charge on an atom, consider
atomic number:
# of p+ 10 Ne --
the whole number
on Periodic Table --
determines identity of atom
mass number:
(# of p+) + (# of n0)
(Isotope mass is NOT on “the Periodic Table.”)
To find net charge on an atom, consider
____ and ____. p+ e–

4. I 53 125 1– Complete Atomic Designation
…gives precise info about an atomic particle
mass #
atomic #
charge (if any)
element
symbol
Goiter due to lack of iodine
iodine is now added to salt I 53
125 1–

5. Isotopes:
different varieties of an element’s atoms --
have diff. #’s of n0; thus, diff. masses --
some are radioactive; others aren’t
All atoms of an element react the same, chemically.
Isotope
Mass p+ n0
Common Name
H–1 1 1
protium
H–2 2 1 1
deuterium
H–3 3 1 2
tritium
C–12 atoms
C–14 atoms
6 p+
6 n0
6 p+
8 n0
stable
radioactive

6. TRANSURANIUM ELEMENT
Element of 93 or greater in the periodic table that is produced in the laboratory by induced transmutation
Transmutation: conversion of an atom of one element to an atom of another element.

7. Radioactivity: process in which some substances spontaneously emit radiation
Radioactive decay: process in which unstable nuclei spontaneously emit radiation

8. FUNDEMENTAL FORCES Pull strength: strongest to weakest 1 Gravity 1/137
1 x 10-6
6 x 10-39
Electromagnetic
Weak
Strong

9. FUNDEMENTAL FORCES Distance of influence: greatest to least
Gravity: influence even between universes
Electromagnetic: repulsive and attractive; limited distance
Weak: nuclear force allows radioactivity
Strong: holds protons together, shortest distance

10. Basic types of Nuclear Reactions
Fusion: two or more nuclei get close enough to react to form new nuclei with possible extra nuclei or particles.
Fission: nuclear reaction or nuclear decay process in which the atoms nucleus splits into smaller parts (nuclei).

11. As the number of protons increases the ratio of neutrons to protons required for stability increases.

12. Rewritten for Nuclear chemistry
Particles we know
Rewritten for Nuclear chemistry
neutron
10n
11H+1
proton
11p+1
00e-1
0-1e
electron

13. Types of particles 
42He2+
Alpha
Beta
0-1e 
positron
0+1e

14. Facts about radiation ALPHA ( 42He )
Heaviest, with a speed of km/s; ~10% of light.
Least penetrating, can be stopped by a sheet of paper.
Impact powerful enough to dislodge 450,000 electrons from affected atoms.
3 cm of air will also stop alpha. Only emitted from heavy elements. If inhaled or ingested can result in serious cell damage.
Basements in some regions need detectors to maintain safe air supply.

15. Facts about radiation BETA ( 0-1e )
Low mass, speed of km/s; ~90% of light.
Moderately penetrating, can be stopped by a sheet of aluminum foil.
3 m of air will also stop beta. Energetic electron emitted to lower energy and stabilize an atom. encounter with a living cell, and there may be many before the beta energy is dissipated, is likely to damage some of the chemical links between the living molecules of the cell or cause some permanent genetic change in the cell nucleus
POSITRON ( 0-1e )
Same as a beta particle

16. Facts about radiation GAMMA RADIATION ( 00g )
photon or high-energy wave
no mass or charge
speed of light
losing ~half its energy for every 153 km
stopped by a thick or dense material
High energy X-ray

17. Facts about the emissions
Magnetic field
00g
Container with
Radiation emitter
42He
Beta’s lack of mass give the field and increased effect. Alpha’s mass reduces the effect but its charge means greater influence of the field
Gamma is not affected by the magnetic field and has no mass (photon)
Magnetic field

18. Facts about radiation NEUTRON ( 10n ) Result of a nuclear fission
Travels thousands of meters through air.
Stopped by hydrogen rich materials; water or concrete.
effectively stopped if blocked by a hydrogen-rich material, such as concrete or water.
Not typically able to ionize an atom directly due to their lack of a charge, they are absorbed into a stable atom, thereby making it unstable and more likely to emit off ionizing radiation of another type. Neutrons are the only type of radiation that is able to turn other materials radioactive.

19. Balancing Nuclear Reactions
Unstable Thorium-232 emit beta particle to achieve a more stable ratio of neutrons to protons 23290Th 0-1b + Pa
23291
232 =
232
90 = 91

20. Try this problem with an a emisson
23692U He +
23290 Th
236 = 4 +
232
92 = 2 + 90

21. Try this problem with a b emisson
146C e + N
147
14 = 14
6 = 7
The proton neutron ratio changed from radioactive carbon-14’s 1::1.3 to stable nitrogen-14’s 1::1

22. Radioactive Isotopes:
have too many or too few n0
Nucleus attempts to attain a lower energy state by releasing extra energy as __________.
radiation
e.g.,
a- or b-particles, g rays
half-life: the time needed for
½ of a radioactive
sample to decay
into stable matter
e.g., C–14: -- half-life is 5,730 years
-- decays into stable N–14

23. Charting Half-life information
# Half-lives 1 2 3 4 5
Time
Increments
Mass / 2
Percents/2
100 50 25
12.5
6.25
3.12
213,000
426,000
639,000
250
125
62.5
500
31.25
effectively stopped if blocked by a hydrogen-rich material, such as concrete or water.
Not typically able to ionize an atom directly due to their lack of a charge, they are absorbed into a stable atom, thereby making it unstable and more likely to emit off ionizing radiation of another type. Neutrons are the only type of radiation that is able to turn other materials radioactive.
What is the half-life of 99Tc if a 500 g sample decays to 62.5 g in years

24. https://www. youtube. com/watch