# Presentation: 139605

## NUCLEAR CONCEPTS

**in**
**EARTH SCIENCE**
**&**
**PHYSICAL SCIENCE**

## KENTUCKY CORE CONTENTfor ASSESSMENTinHigh School Science

## BIG IDEA: EARTH AND THE UNIVERSE(Earth/Space Science)

**Notes:**
Some stars explode at the end of their lives, and the heavy elements they have created are blasted out into space to form the next generation of stars and planets.

##   SC-HS-2.3.3

-    Students will explain the origin of heavy elements in planetary objects (planets & stars)

##      SC-HS-2.3.4

-       Students will understand that stars
-       generate energy from nuclear fusion
-       reactions that create successively
-       heavier chemical elements.

##    SC-HS-2.3.6

-    Students will compare the limitations/ benefits of various techniques for estimating geologic time (radioactive dating, observing rock sequences, and comparing fossils).

**Notes:**
Current methods include using the known decay rates of radioactive isotopes present in rocks to measure the time since the rock was formed.

## BIG IDEA:  ENERGY TRANSFORMATIONS (Unifying Concepts)

**Notes:**
Two primary sources of internal energy are the decay of radioactive isotopes and the gravitational energy from Earth’s original formation.

## SC-HS-4.6.8

- Students will:
- describe the connections between the functioning of the Earth system and its sources of energy (internal and external)
- predict consequences of changes to any component of the Earth system

## SC-HS-4.6.11         

- Students will:
- explain the difference between alpha and beta decay, fission, and fusion;
- identify the relationship between nuclear reactions and energy.

**Notes:**
Nuclear reactions convert a fraction of the mass of interacting particles into energy, and they can release much greater amounts of energy than atomic interactions.
Fusion is the process responsible for the energy of the sun and other stars.

## SC-HS-4.6.12

-    Students will understand that the forces that hold the nucleus together, at nuclear distances, are usually stronger than the forces that would make it fly apart.

**EARTH**
**SCIENCE**

## Lessons 1-2Absolute-Age Dating of Rocks 

- (2.3.6 & 4.6.8)
- OBJECTIVES:
- Explain several different methods used by scientists to determine absolute age of rocks.
- Define isotopes.
- Describe how objects are dated by the use of certain radioactive elements.
- Describe the evidence used to determine the age of the Earth.

## KEY TERMS

- decay rate
- half-life
- nuclear radiation
- radioactive decay
- radioisotopes
- radiometric dating

## WORKSHEETS

- Radioactive Decay
- Half-Life
- Absolute-Age Dating of Rocks
- Radioactive Dating

## LAB ACTIVITIES

- Measuring Background Radiation
- Simulating Half-Life
- Modeling C-14 Decay Curve

## OPEN RESPONSE QUESTIONS

- Radioactive Decay
- Radiometric Dating
- Carbon Dating

## A-V MATERIALS

- Videos:  _A Look at Radiation_ and _Managing Radiation_ (from National Safety Council)

## GOING FURTHER

- Obtain a radon test kit from the local health department and test your home for radon gas.

- PHYSICAL
- SCIENCE

## Lesson 1Radioactive Elements  (4.6.12)

## Objectives:

- Describe Becquerel’s discovery of radiation.
- Define radioactivity.
- Define binding energy.
- Compare radioactive and stable isotopes.

## KEY TERMS

- binding energy
- radiation
- radioactivity
- radioisotopes

## WORKSHEETS

- Radioactivity

## LAB ACTIVITIES

- Making Radiation Photographs (from ANS)
- Measuring Background Radiation

## Lesson 2Radioactive Decay    (4.6.11)

## Objectives:

- Define radioactive decay.
- Describe alpha, beta, and gamma radiation.
- Read and interpret graphs illustrating decay series.
- Interpret, write, and balance nuclear equations.
- Explain and apply the concept of half-life.

## KEY TERMS

- alpha particle
- beta particle
- gamma radiation
- decay series
- half-life
- radioactive decay

## WORKSHEETS

- Writing Nuclear Equations
- Decay Series of Uranuim-238
- Nuclear Decay
- Nuclear Equations
- Graphing Half-life

## LAB ACTIVITY

- Modeling Half-Life

## LESSON 3Harnessing the Nucleus  (4.6.11)

## Objectives:

- Describe the processes of nuclear fission and fusion.
- Trace the events in a nuclear chain reaction and explain the origin of the energy released.
- Explain how energy from fission is converted to electricity in a nuclear reactor.
- Describe the parts of a nuclear reactor.

## KEY TERMS

- Fission
- Fusion
- Nuclear chain reaction
- Core
- Moderator
- Control rods
- Heat exchanger

## WORKSHEETS

- Nuclear Chain Reaction
- Fission and Fusion
- Nuclear Reactor
- Harnessing the Nucleus
- Pressurized-Water Reactor Diagram (NRC website)
- Boiling-Water Reactor Diagram (NRC website)

## LAB ACTIVITY

- Modeling a Chain Reaction

## LESSON 4Detecting, Measuring, and Using Radioactivity   (4.6.11)

## Objective 1

- Describe the structure and use of the :
-   electroscope
-   Geiger counter
-   cloud chamber
-   photographic film

## KEY TERMS

- electroscope
- Geiger counter
- cloud chamber
- radioisotope
- tracer

## The Gold Leaf Electroscope   

-  When an electroscope is charged, the gold leaf sticks out, because the charges on the gold repel like charges on the metal rod.
- When a radioactive source comes near, the air is ionized, and starts to conduct electricity. This means that the charge can "leak" away, the electroscope discharges and the gold leaf falls.

## Geiger Counter

- This is actually a _[Geiger-](http://www.darvill.clara.net/nucrad/people.htm#geiger)__[Müller](http://www.darvill.clara.net/nucrad/people.htm#geiger)_ tube with some form of counter attached, which usually tells us the number of particles detected per minute ("counts per minute").
- GM tubes work using the _[ionizing](http://www.darvill.clara.net/nucrad/ionise.htm)_ effect of radioactivity.

## Cloud Chamber

- The chamber contains a supersaturated vapor which condenses into droplets when disturbed and ionized by the passage of a particle.
- The droplets form a trail in the chamber.

## Photographic Film

- In 1896, Henri _[Becquerel](http://www.darvill.clara.net/nucrad/people.htm#becquerel)__ discovered that uranium compounds would darken a photographic plate, even if the plate were wrapped up so that no light could get in._
- The amount of “fogging” or darkening is determined by how much radiation strikes the film.

## Photographic Film

- Workers in the nuclear industry wear "film badges" which are then developed.
-  This allows for the measurement of the dose that each worker has received.

## Objective 2

- Describe the use of radioisotopes in:
-  studying organisms
-  diagnosing and treating disease
-  sterilizing food
-  monitoring industrial processes

## Radioactive Dating

- Animals and plants have a known proportion of carbon-14 in their tissues.
- When they die, the amount of C-14 goes down at a known rate.
- Since C-14 has a half-life of about 5700 years, the age of ancient organic materials can be found by measuring the amount of C-14 that is left.

## Radioactive Tracers

- Radioisotopes are frequently used as tracers whose pathways through the steps of chemical reactions may be traced.
- These may be used for medical purposes such as checking for blockages or circulatory problems.

## Cancer Treatments

- Because gamma rays can kill living cells, they are used to kill cancer cells without having to resort to difficult surgery.
- This is called radiation therapy and works because cancer cells cannot repair themselves when damaged as healthy cells can.

## Sterilizing

- Even after it has been packaged, gamma rays can be used to kill bacteria, mould and insects in food.
- This process prolongs the shelf-life of the food.
- Gamma rays are also used to sterilize hospital equipment, especially plastic syringes that would be damaged if heated

## Industrial Processes

- Radioisotopes may be used in industry to detect leaking pipes. To do this, a small amount is injected into the pipe. It is then detected with a GM counter above ground.
**Checking welds:  **a gamma source is placed on one side of the welded metal and a photographic film on the other side. Weak points or air bubbles will show up on the film, like an X-ray.

## WORKSHEETS

- Estimate Your Personal Radiation Dose
- Atomic Crossword (NRC website)
- Test Your Nuclear Knowledge Quiz  (NRC website)

## LAB ACTIVITY

-  Radiation and Shielding

## OPEN RESPONSE QUESTIONS

- Radioactive Decay
- Radioactive Dating
- Carbon Dating

## RESEARCH

- Nuclear Weapons
- Nuclear Power Plants

## MEDIA ITEMS

- Videos:  _A Look at Radiation_ and _Managing Radiation_ ( a free kit from The National Safety Council: http://www.nsc.org/issues/radisafe.htm)
- Website of Nuclear Regulatory Commission:  _[http://www.nrc.gov/reading-rm/basic-ref/students.html](http://www.nrc.gov/reading-rm/basic-ref/students.html)_  (student activities)

## GOING FURTHER

- Obtain a radon test kit and test your home for the presence of radon gas.
-   (These may be obtained free-of-charge from some local health departments.)

## GOING FURTHER

- Observe radiation flashes by looking at a Fiestaware plate through a magnifying glass in a totally dark room.
-   (First allow a few minutes for your eyes to adjust to the darkness.)