Menu
CoddyPhysics
START LEARNING

Radioactive Dating

Part of the Optics, Waves and Modern Physics section of Coddy's Physics journey. Lesson 48 of 53.

Living things keep a steady share of carbon-14 (T = 5730 years); after death it decays.

Carbon-14 decay

Count half-lives, or take logs:

t = T ln(A₀/A) / ln 2

challenge icon

Challenge

A piece of wood has a carbon-14 activity of 0.0625 Bq per gram; living wood has 0.25 Bq per gram. How old t is the wood, in years?

Try it yourself

quiz iconTest yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Optics, Waves and Modern Physics

1Reflection and Refraction

Reflection of LightThe Refractive IndexSnell's LawTotal Internal ReflectionDispersionApparent DepthRecap - Optical Fiber

4Mechanical Waves

What a Wave IsTwo Graphs of a WaveWhen Pulses MeetInterferenceStanding WavesHarmonicsRecap - Guitar String

7Photons

Light Comes in PhotonsThe Photoelectric EffectEinstein's EquationStopping VoltageCounting PhotonsRecap - Solar Cell

10Nuclear Energy

Mass DefectBinding Energy per NucleonFission and FusionRecap - Inside the Sun

2Plane Mirrors

The Image in a MirrorSeeing in a MirrorTwo MirrorsRecap - Periscope

5The Ripple Tank

Two SourcesNodal LinesHow the Pattern ChangesRecap - Two Speakers

8The Bohr Atom

The Bohr ModelEmission and AbsorptionSpectral LinesRecap - Hydrogen Lamp

3Thin Lenses

Lenses and Their RaysThe Lens EquationVirtual ImagesTwo LensesA Lens and a MirrorRecap - Build a Projector

6Light as a Wave

Light Through Two SlitsFringes on a ScreenDiffraction by One SlitThe Diffraction GratingRecap - Measure with a CD

9The Nucleus

Inside the NucleusRadioactive DecayHalf-LifeActivityRadioactive DatingRecap - Carbon Dating