Nuclear Chemistry

Front 1

two cities that atomic bombs were dropped on in WWII

Back 1

Hiroshima and Nagasaki

Front 2

Nuclear Chemistry

Back 2

study of changes in structure of nuclei and subsequent changes in chemistry.

Front 3

Radioactive nuclei

Back 3

spontaneously change structure and emit radiation.

Front 4

Number of Protons is called

Back 4

Atomic Number

Front 5

Number of protons and neutrons is effectively

Back 5

mass of the atom

Front 6

Three naturally occurring isotopes of uranium

Back 6

Uranium-234
Uranium-235
Uranium-238

Front 7

NUCLEONS ARE MADE UP OF

Back 7

PROTONS AND NEUTRONS

Front 8

NUCLIDE IS AN ATOM IDENTIFIED BY

Back 8

THE NUMBER OF PROTONS AND NEUTRONS

Front 9

NUCLEAR FORCE IS

Back 9

THE FORCE THAT HOLDS TWO PROTONS THOGETHER OVERCOMING ELECTROSTATIC INTERACTION

Front 10

What is Mass Defect

Back 10

Difference between the mass of an atom and the mass of its individual particles.

Front 11

What is Nuclear Binding Energy

Back 11

Energy released when a nucleus is formed from nucleons.

High binding energy = stable nucleus

Front 12

What is the characteristic of Unstable Nuclides

Back 12

They are radioactive and undergo radioactive decay

Front 13

What is the Band of Stability

Back 13

Nuclear force balanced with electrostatic interactions
1:1 neutron to proton ratio is stable.
Above 1:1.5 not stable
Below 1:1 not stable
As atoms get larger, neutrons help stabilize nucleus.

Front 14

Radioactive Decay

Back 14

Nucleus held together by strong attractive forces; but electrostatic repulsion causes large atoms (>83 protons) to be unstable.
disintegration of a nucleus into a slightly lighter nucleus, accompanied by emission of particles, electromagnetic radiation (emr), or both

Front 15

Nuclear Reactions

Back 15

CHANGES THE NUCLEUS OF A REACTION

Front 16

Nuclear radiation:

Back 16

particles or electromagnetic radiation emitted from the nucleus during radioactive decay

Front 17

Radioactive nuclide:

Back 17

an unstable nucleus that undergoes radioactive decay

Front 18

4 Types of Radioactive Decay

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Alpha Particle Charge= 2+
Beta Patricle Charge= 1_
Positron Charge= 1+
Gamma Ray Charge= 0

Front 19

Alpha Decay

Back 19

Loss of an a-particle (a helium nucleus)
Reduce the number of protons and neutrons (atoms atomic # >82)
Increased n:p ratio

Front 20

Beta Decay

Back 20

Loss of a B-particle (a high energy electron)
Neutron to proton ratio high
Neutron converted to proton and electron

Front 21

Positron Emission

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Loss of a positron (a particle that has the same mass as but opposite charge than an electron)
Neutron to proton ratio low
Proton converted to neutron and positron

Front 22

Gamma Emission

Back 22

Loss of a g-ray (high-energy radiation that almost always accompanies the loss of a nuclear particle).
Immediately follows other types of decay.

Front 23

Electron Capture (K-Capture)

Back 23

Addition of an electron to a proton in the nucleus
Neutron to proton ratio is low
As a result, a proton is transformed into a neutron.
Emit a positron

Front 24

What does Uranium-238 make if it undergoes an alpha radiation decay?

Back 24

It will decay (lose an alpha particle) into Thorium-234.

Front 25

What is Half Life

Back 25

Time required for half of the atoms of a radioactive nucleotide to decay

All specific amounts of time for specific elements

Front 26

Phosphorus-32 has a half-life of 14.3 days. How many grams of phosphorus-32 remain after 57.2 days if you start with a 4 g sample?

Back 26

57.2 days = 4 half-lives pass 14.3 days

4 half-lives = 1/16 or 6.25%
6.25% of 4 g = 0.0625 x 4g
= 0.25 g remains

Front 27

Who accidentally discovered Roadiactivity

Back 27

Henry Becquerel in 1896
Studied uranium compounds

Front 28

Who also discovered Radioactivity

Back 28

Marie Skłodowska-Curie & Pierre Curie
Lab assistants of Becquerel
Worked with “pitchblend” (uranium ore)
Discovered U & Th are radioactive (1896)
Discovered 2 new radioactive elements
Po & Ra

Front 29

Roentgen and the X-ray

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Discovered gamma rays expose film and applied to humans

Front 30

Properties of Radioactive elements

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1. Affect light-sensitive photographic film
2. produce an electric charge in the surrounding air
3. Produce fluorescence with certain other compounds
4. Have special physiological effects Ex) kill bacteria, kill living cells, treat cancer
5. Undergo radioactive decay and has a half-life

Front 31

Meter used to measure Nuclear Radiation

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Geiger-Müller Counter – detect radiation by counting electric pulses carried by gas ionized by radiation
Audible clicks w/ A speaker attached
Used in TV/Movies

Front 32

Radioactive Dating

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process by which the approximate age of an object is determined based on the amount of certain radioactive nuclides present
Ex) carbon dating

Front 33

Radioactive Tracers

Back 33

radioactive atoms that are incorporated into substances so that movement of the substances can be followed by radiation detectors

Front 34

How was Nuclear Radiation used to for Thyroid Disease (Graves’ Disease aka Goiters)

Back 34

drink iodine-131
Iodine uptake is measured
“Iodized” Salt!

Front 35

Radiation can be used to detect what disorders

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1. Brain Tumors & Liver Disorders: Use technetium-99m
2. Skin Cancer : Use phosphorus-32

Front 36

What is Fusion?

Back 36

A nuclear reaction in which atomic nuclei of low atomic number fuse to form a heavier nucleus with the release of energy.

Front 37

Applications of Fusion

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1. The Sun

2. Fusion Bomb

Front 38

What is Fission?

Back 38

Atomic nuclei of high atomic number split into smaller lighter nuclei producing free neutron and photons with the release of energy.

Chain Reaction

Front 39

What is Critical mass

Back 39

The minimum amount of nuclide that provides the number of neutrons required to sustain a nuclear reaction.

Front 40

Hydrogen Bomb Stage 1(Standard Atomic Bomb)

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High explosives combine two subcritical masses to form a supercritical mass.
Based on Fission
Standard atomic bomb (dropped on Japan)

Front 41

Hydrogen bombSecond stage

Back 41

Fission creates high pressure and temperature required for fusion
In a hydrogen bomb, two isotopes of hydrogen, deuterium and tritium are fused to form a nucleus of helium and a neutron.

Front 42

What good things can we do using the same reaction as the one used in a nuclear bomb

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Energy: Nuclear reactor, controlled fission

Front 43

How does a nuclear reactor control fission

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Fuel rods: Usually Uranium -235. Fission reaction releases energy which heats water to create steam.
Control rods
Used to control reaction by absorbing neutrons – usually a boron steel alloy

Front 44

What happens if the control rods fail

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Meltdown: the nuclear reaction grows uncontrolled and generates enough heat to melt through the containment vessel and leak into the atmosphere

Front 45

WHat were the names of the bombs used in Hiroshima and Nagasaki

Back 45

Fat Man and Little Boy