Drinking Dinosaur Pee?!
It has been claimed that because all water ultimately ends up in the water cycle, we drink water that the dinosaurs peed out. What does chemistry have to say about this assertion?
It has been claimed that because all water ultimately ends up in the water cycle, we drink water that the dinosaurs peed out. What does chemistry have to say about this assertion?
Two important types of information obtained from ice cores comes from the bubbles in the glacial ice and the stable oxygen and hydrogen isotopes within the frozen water molecules themselves. This post describes how the bubbles (air pocket 'fossils') and stable isotopes are used to determine the concentration of gases in the ancient atmosphere, particularly in relation to past temperatures.
In this activity, students can look inside the model that resembles the atom and find information that reinforces what an isotope actually is. Furthermore, the quantitative data forces students to examine beliefs about different types of averages and what the numbers really mean. This takes a bit of effort to set up but is inexpensive and can be used year after year.
This is the first isotope activity I have tried where the students can look inside the model that resembled the atom and find information that reinforced what an isotope actually is. Furthermore, the quantitative data forced them to examine beliefs about different types of averages and what the numbers really mean.
After receiving positive feedback from Peter Mahaffy, the IUPAC project co-chair of Isotopes Matter, I decided to add an additional component to the original isotope assignment I posted. The second component of the assignment focuses on the applications of both radioactive and stable isotopes using the interactive IUPAC periodic table.
College Board offers an excellent online resource for teachers and students. It's not free, but my school district pays the bill. AP Insight provides curriculum outlines, teaching ideas and resources, student handouts, and digitally-graded assessments.
An ice cube made from normal water floats in a beaker of liquid water.
An ice cube of deuterium oxide (containing a heavier isotope of hydrogen) sinks in water.
A normal ice cube is less dense than liquid water, but a deuterium oxide ice cube is more dense than liquid water.
An H2O ice cube is less dense than liquid water, but a D2O ice cube is more dense than liquid water.