Making a mass spectrometer!

Scientists carbon date ancient artifacts using a machine called a mass spectrometer. 

A mass spectrometer separates atoms by, you guessed it, their mass. When carbon dating an artifact, like a mummy, scientists look at a ratio of two atoms – Carbon 12 which is stable, and radioactively decaying Carbon 14.

Carbon 14 weighs slightly more than Carbon 12.

Not much more though – just about two neutrons more (since Carbon 12 and Carbon 14 differ by the addition of two neutrons in the later). To measure the amount of C12 and C14 we need to separate them, which is where a mass spectrometer comes in. Because of their slightly different masses, they go to different places on the mass spectrometer.

Scientists then use the ratio of the two (C14/C12) to determine how old an object is!

Mass spectrometers are like big black boxes to kids (and most adults). We were searching and searching for a fun hands-on way to learn about carbon dating when this idea popped into Dr. Erica’s head (which was then much refined by Dad tester Evan).

What if we created a DIY homemade mass spectrometer out of a ramp and a blow dryer?!?

These items are easily found around the house, and they follow the same principles that a real mass spectrometer uses.

Let’s break down the comparison of our homemade mass spectrometer to the real deal.

  • It accelerates coins using a regular force field (in a mass spectrometer this is an electric field, in our DIY spectrometer this is the force of gravity).
  • It utilizes a secondary force and object qualities to alter the path of the object (in a mass spectrometer this is a magnetic field that changes based on the speed and charge of the particle, in our homemade mass spectrometer this is the force of the blow dryer that changes based on cross-section and mass of the coin)
  • It separates¬†objects based on mass (in a mass spectrometer this can be atoms like C12 and C14, in our DIY mass spectrometer this is the type of coin)

Our homemade spectrometer can effectively sort pennies from nickels. One of the projects in our chicken mummy lab is now to take a bag of mixed pennies and nickels and determine how many there are with our spectrometer. We can then use a chart (yay graphical reading) to determine via ‘carbon dating’ if our mummy is the real deal or a total fake!

You can see Dr. Erica explain it here on YouTube!¬†Don’t forget to subscribe to our YouTube channel! We post tons of great videos about all aspects of each lab!