Fun with the Isotopes the Chocolate Plate

CCST9019 Isotope (Chocolate) Lab

2011

Fun With isotopes – the Chocolate Lab

LAB MODULE I SOTOPES & PALEOCLN

CCST9019 Understanding Climate Change

Fun With Isotopes…

This week we will use an fun tutorial resource explaining isotope fractionation, using (sorry) virtual Chocolate and Ping Pong balls… :D *(the Chocolate portion is modified from Brian Fry’s Stable Isotope Ecology)

1

CCST9019 Isotope (Chocolate) Lab

2011

Introduction

Chocolate Isotopes

For most of us, the whole concept of isotopes is hard to grasp, seemingly simple, yet often mysterious. To help visualize the fractionation process, try this just-for-fun example, chocolate isotopes. Now, there are no such things as chocolate isotopes, but then again, there is nothing to stop us from inventing some for our virtual entertainment. Isotopes are just different ‘flavours’ of the same Element, so why not enlist chocolate as a virtual element? In natural process, such as evaporation, isotope fractionation occurs at the atomic level, where bonds are broken and formed. Down there at the atomic level, the probabilities of quantum theory dictate that heavy-isotope bonds are slower to react than the light-isotope bonds. But in this chocolate example, we create an alternate universe where it is us who do the selection, not quantum probabilities. So, here you go.

Figure 1 Chocolate!

In our yummy alternate universe, you have 100,000 pieces of chocolate and you eat 1000 pieces every day (with no consequence, because this is a virtual universe, one that is definitely worth visiting in your dreams:). But already you may see the flaw: soon you would feel bad, because every day there would be 1000 fewer pieces of chocolate, and you know the day would come when—Oh No!—no more chocolate! Happily, to forestall this catastrophe, we have a Benevolent Chocolate God (BCG) who adds back 1000 pieces of chocolate every day, so the mountain of chocolate never grows smaller, never disappears, but always...