deposition (phase transition)

Deposition (phase transition) Deposition of water causes humid air to condense into frost pat- terns, for example in single-layer window glasses and wind- shields Deposition, also known as desublimation, is a thermodynamic process,a phase transition in which gas transforms into solid. The reverse of deposition is sublimation. One example of deposition is the process by which, in sub-freezing air, water vapor changes directly to ice with- out first becoming a liquid. This is how snow forms in clouds, as well as frost and hoar frost on the ground. An- other example is when frost forms on a leaf. For deposition to occur, thermal energy must be removed from a gas. When the leaf becomes cold enough, water vapor in the air surrounding the leaf loses enough thermal energy to change into a solid. Deposition in water vapor occurs due to the pureness of the water vapor. The vapor has no for- eign particles, and is therefore able to lose large amounts of energy before forming around something. When the leaf is introduced, the supercooled water vapor immedi- ately begins to condensate, but by this point is already past the freezing point. This causes the water vapor to change directly into a solid. Another example of physical deposition is the artificial process of physical vapor deposition, used to deposit thin films of various materials onto various surfaces. Deposition releases energy and is an exothermic phase change. 1 References • Jacobson, Mark Z., Fundamentals of Atmospheric Modeling, Cambridge University Press, 2nd ed., 2005, p. 525 ISBN 978-0-521-83970-9 • Moore, John W., et al., Principles of Chemistry: The Molecular Science, Brooks Cole, 2009, p. 387 ISBN 978-0-495-39079-4 • Whitten, Kenneth W., et al., Chemistry, Brooks- Cole, 9th ed., 2009, p. 7 ISBN 978-0-495-39163-0 • Glencoe Science “Focus on Physical Science” 1

Upload: ruin2832

Post on 14-Nov-2015

215 views

Category:

Documents

2 download

Report

Download

Embed Size (px):

DESCRIPTION

sci

TRANSCRIPT

Deposition (phase transition)

Deposition of water causes humid air to condense into frost pat-terns, for example in single-layer window glasses and wind-shields

Deposition, also known as desublimation, is athermodynamic process, a phase transition in whichgas transforms into solid. The reverse of deposition issublimation.One example of deposition is the process by which, insub-freezing air, water vapor changes directly to ice with-out rst becoming a liquid. This is how snow forms inclouds, as well as frost and hoar frost on the ground. An-other example is when frost forms on a leaf. For deposi-tion to occur, thermal energymust be removed from a gas.When the leaf becomes cold enough, water vapor in theair surrounding the leaf loses enough thermal energy tochange into a solid. Deposition in water vapor occurs dueto the pureness of the water vapor. The vapor has no for-eign particles, and is therefore able to lose large amountsof energy before forming around something. When theleaf is introduced, the supercooled water vapor immedi-ately begins to condensate, but by this point is already pastthe freezing point. This causes the water vapor to changedirectly into a solid.Another example of physical deposition is the articialprocess of physical vapor deposition, used to deposit thinlms of various materials onto various surfaces.Deposition releases energy and is an exothermic phasechange.

1 References Jacobson, Mark Z., Fundamentals of AtmosphericModeling, Cambridge University Press, 2nd ed.,2005, p. 525 ISBN 978-0-521-83970-9

Moore, JohnW., et al., Principles of Chemistry: TheMolecular Science, Brooks Cole, 2009, p. 387 ISBN978-0-495-39079-4

Whitten, Kenneth W., et al., Chemistry, Brooks-Cole, 9th ed., 2009, p. 7 ISBN 978-0-495-39163-0

Glencoe Science Focus on Physical Science

1
2 2 TEXT AND IMAGE SOURCES, CONTRIBUTORS, AND LICENSES

2 Text and image sources, contributors, and licenses2.1 Text

Deposition (phase transition) Source: http://en.wikipedia.org/wiki/Deposition_(phase_transition)?oldid=610780583 Contributors:Glenn, Emperorbma, Bearcat, Xanzzibar, Giftlite, Vsmith, BlueNovember, Alansohn, Zippo, Knuckles, Ozabluda, Dhollm, Vicarious,SmackBot, Nberger, Wine Guy, Radagast83, Cybercobra, Cydebot, Satori Son, PKT, Headbomb, OuroborosCobra, Elert, Inks.LWC,Gabriel Kielland, Bakazan, EscapingLife, Melamed katz, Sigmundur, STBotD, Bcnof, Mun206, JhsBot, Synthebot, Falcon8765, Caltas,Hxhbot, ClueBot, Ideal gas equation, Djr32, Addbot, Haruth, Kyle1278, 5 albert square, Tide rolls, Loupeter, Sternmusik, Erik9bot,DixonDBot, Skakkle, ZroBot, A2soup, RockMagnetist, ClueBot NG, Greatestguy, Helpful Pixie Bot, Snaevar-bot, UAwiki, Rm1271,ChrisGualtieri, Zqrrld, Epicgenius, Bobbyblee and Anonymous: 55

2.2 Images File:Frost_patterns_4.jpg Source: http://upload.wikimedia.org/wikipedia/commons/5/51/Frost_patterns_4.jpg License: CC-BY-SA-3.0

Contributors: Own work Original artist: Schnobby File:Phase_change_-_en.svg Source: http://upload.wikimedia.org/wikipedia/commons/0/0b/Phase_change_-_en.svg License: Public

domain Contributors: Own work Original artist: F l a n k e r, penubag File:Text_document_with_red_question_mark.svg Source: http://upload.wikimedia.org/wikipedia/commons/a/a4/Text_document_

with_red_question_mark.svg License: Public domain Contributors: Created by bdesham with Inkscape; based upon Text-x-generic.svgfrom the Tango project. Original artist: Benjamin D. Esham (bdesham)

2.3 Content license Creative Commons Attribution-Share Alike 3.0

ReferencesText and image sources, contributors, and licensesTextImagesContent license