OK. More of a poll, really, than a quiz. Answer this question without consulting a dictionary or other reference text, just based on your present understanding.

Remember to come to the forum to post your response.

QESTION: Which of the following best describes the term "STEAM"

A) Water in the gaseous phase that you can see rising from a pot of boiling water.

B) Tiny water droplets in the liquid phase that you can see rising from a pot of boiling water.

C) Water in the gaseous phase that you cannot see that results from water reaching its boiling point.

D) The mixture of gaseous water and liquid water droplets that arise from a pot of boiling water.

E) Other

Please explain your answer if possible, but "just a hunch" is OK too.

-- Michael Gatton (mgatton@adiglobal.com), September 15, 2002

Answers

Response to A QUIZ: Just for fun

I will say Steam is D a mixture of water droplets and gas that arise from a pot of boiling water. So to explain this let me say that when the molecules of water get excited because of the heat they change phases to gas and escape the liquid but as they leave the temperature of the air is cooler than the water so the gas condenses into water droplets. So it is a mixture.

How does that sound?

-- Deanna Zapata (zapatad75@msn.com), September 15, 2002.

Response to A QUIZ: Just for fun

I would definitely not say steam is a mixture of gaseous water and water droplets because steam is purely water vapor. The droplets are a result of condensation. It can be confusing because commonly both phenomena usually occur simultaneously.I would say that the correct answer is A because steam is water in the gas phase that is usually visible.

-- Edward Palmer (epalmer@nyc.rr.com), September 15, 2002.

There are certain terms that should be used carefully in science class because of wide-spread confusion over their meanings. The word steam is a good example that was used recently in a class I am taking at CCNY. Steam was the "correct" answer to a question concerning the content of the bubbles that form at the bottom of a pot of boiling water (and of course rise to the top and release their contents into the surroundings). I had always thought that steam was: Tiny water droplets in the liquid phase that you can see rising from a pot of boiling water (B). The professor said "No, steam is just water in the gaseous phase (C)," as far as he knew, but he would check into it. He consulted with two chemists at Columbia, who each had different answers corresponding to the two different definitions just mentioned.

The confusion arises from the scientific definition of the term being at odds with the common usage of the word. Strictly speaking, steam is water in the gaseous phase. Gaseous water is invisible, so answer "A" cannot be correct. In common usage, however, steam also denotes the misty condensed water (liquid phase) that we often see coming from a boiling pot or hot shower or what ever. So, answer C is correct in a strictest sense, but answer B is also correct according to popular usage. I suppose you could put B & C together and get D, but I’ve not seen any references that actually use that phraseology (“a mixture” of the two). For more information check out dictionary.com's reference to steam.

Thanks to Ed and Deanna for responding to this week’s quiz/poll!

ADDENDUM

The term steam could be useful in discussing energy conversions in the context of steam engines (heat energy into mechanical energy). The important factor being: "When water is boiled into steam its volume increases about 1,600 times, producing a force that can be used to move a piston back and forth in a cylinder."
(The Concise Columbia Encyclopedia)

Just remember that steam here refers to water in the gaseous phase.

-- Michael Gatton (mwgatton@hotmail.com), September 18, 2002.