Archives of Ask A Scientist!
About "Ask A Scientist!"
On September 17th, 1998 the Ithaca Journal ran its first "Ask A Scientist!" article in which Professor Neil Ashcroft , who was then the director of CCMR, answered the question "What is Jupiter made of?" Since then, we have received over 1,000 questions from students and adults from all over the world. Select questions are answered weekly and published in the Ithaca Journal and on our web site. "Ask A Scientist!" reaches more than 21,000 Central New York residents through the Ithaca Journal and countless others around the world throught the "Ask a Scientist!" web site.
Across disciplines and across the state, from Nobel Prize winning scientist David Lee to notable science education advocate Bill Nye, researchers and scientists have been called on to respond to these questions. For more than seven years, kids - and a few adults - have been submitting their queries to find out the answer to life's everyday questions.
Now suppose you took your glass of water from the countertop and sealed it inside a somewhat larger, airtight container. What do you think would happen? If you observe the process over a period of time, you will see the water level drop initially and then (if you started with enough water) evaporation will seem to stop. Your closed system has reached equilibrium: There is enough water vapor in the closed container that molecules are condensing back onto the surface at the same rate as they evaporate. The rate of evaporation is different for different liquids. For instance, alcohol evaporates more quickly than water, while oils takes much longer.
The rate of evaporation also depends on the temperature of the liquid and its surroundings. Some heavy oils (or exotic liquids like liquid mercury) may need to be heated before they show appreciable evaporation.
If you raise the temperature of a liquid enough you can start a process of evaporation within the liquid itself. This process is another very familiar one-it's called boiling!
- Why do baseballs fly farther in Coors Field in Colorado?
- Why does each snowflake have a different shape?
- How can information be sent on radio waves, etc? How can things that have no mass contain messages?
- Why do scuba divers wear rubber?
- Why can't you put metal in a microwave?
- How do they compress oxygen into pure oxygen tanks?
- Why do we get a shock from electricity?
- I have heard of ways to get energy through the braking of a car. How does this work?
- Why does wood turn to ashes in my fireplace?
- How do you make a rock into a metal or a crystal?