chapter 25 nuclear chemistry iii. fission & fusion (p. 717 - 719) iii. fission & fusion (p....

CHAPTER 25

Nuclear

Chemistry

CHAPTER 25

Nuclear

ChemistryIII. Fission & III. Fission &

FusionFusion(p. 717 - 719)

III. Fission & III. Fission & FusionFusion

(p. 717 - 719)

I

IV

III

II

A. FA. F issionissionA. FA. F issionission Nuclear Reactions produce exponentially more

energy than chemical reactions. (nuclear bomb vs. dynamite chemical bombs)

Fission is splitting a nucleus into two or more smaller nuclei 1 g of 235U =

3 tons of coal

U23592

A. FA. F issionissionA. FA. F issionissionchain reaction - self-propagating reactioncritical mass -

mass required to sustain a chain reaction

Super-critical is

when chain rxn

goes too fast…

MELTDOWN

B. FusionB. FusionB. FusionB. Fusioncombining of two nuclei to form one nucleus of larger mass thermonuclear reaction – requires temp of 40,000,000 K to sustain1 g of fusion fuel =

20 tons of coaloccurs naturally in

stars

HH 31

21

C. Fission vs. FusionC. Fission vs. FusionC. Fission vs. FusionC. Fission vs. Fusion

235U is limited danger of meltdown toxic waste thermal pollution

Heavy hydrogen fuel is abundant

no danger of meltdown no toxic waste not yet sustainable

FISSION

FUSION

CHAPTER 25

Nuclear

Chemistry

CHAPTER 25

Nuclear

ChemistryIV. ApplicationsIV. ApplicationsIV. ApplicationsIV. Applications

I

IV

III

II

A. Nuclear PowerA. Nuclear PowerA. Nuclear PowerA. Nuclear Power

Fission Reactors Cooling Tower

A. Nuclear PowerA. Nuclear PowerA. Nuclear PowerA. Nuclear Power

Fission Reactors

A. Nuclear PowerA. Nuclear PowerA. Nuclear PowerA. Nuclear Power

Fusion Reactors (not yet sustainable)

A. Nuclear PowerA. Nuclear PowerA. Nuclear PowerA. Nuclear Power

Fusion Reactors (not yet sustainable)

Tokamak Fusion Test Reactor

Princeton University

National Spherical Torus Experiment

B. Synthetic ElementsB. Synthetic ElementsB. Synthetic ElementsB. Synthetic Elements

Transuranium Elements elements with atomic #s above 92 synthetically produced in nuclear reactors and accelerators most decay very rapidly

Pu He U 24294

42

23892

C. Radioactive DatingC. Radioactive DatingC. Radioactive DatingC. Radioactive Dating

half-life measurements of radioactive elements are used to determine the age of an object

decay rate and amount of radioactive material remaining indicate the age

EX: 14C – can date ages of up to 40,000 years238U and 40K - over 300,000 years

old

PET ScanPET ScanPET ScanPET ScanPositron Emission Topography Inject or swallow a sugar with a

radioactive tag that emits positron, which are measured by a scanner

D. Nuclear MedicineD. Nuclear MedicineD. Nuclear MedicineD. Nuclear Medicine

Radioisotope Tracers (bonded to sugars, proteins, or medicines) absorbed by specific organs and used to diagnose

diseases

Radiation Treatment larger doses are used

to kill cancerous cells in targeted organs

internal or external radiation source

Radiation treatment using-rays from cobalt-60.

E. Nuclear WeaponsE. Nuclear WeaponsE. Nuclear WeaponsE. Nuclear Weapons

Atomic Bomb chemical explosion is used to form a critical

mass of 235U or 239Pu fission develops into an uncontrolled chain

reaction

Hydrogen Bomb chemical explosion fission fusion fusion increases the fission rate more powerful than the atomic bomb

F. OthersF. OthersF. OthersF. Others

Food Irradiation radiation is used to kill bacteria

Radioactive Tracers explore chemical pathways trace water flow study plant growth, photosynthesis

Consumer Products ionizing smoke detectors - 241Am