{"id":2592,"date":"2016-08-24T13:47:37","date_gmt":"2016-08-24T13:47:37","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/?post_type=chapter&#038;p=2592"},"modified":"2017-08-28T21:49:20","modified_gmt":"2017-08-28T21:49:20","slug":"surface-tension","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/chapter\/surface-tension\/","title":{"raw":"Surface Tension","rendered":"Surface Tension"},"content":{"raw":"<div class=\"x-ck12-data-objectives\">\r\n<div class=\"textbox learning-objectives\">\r\n<h3>Learning Objectives<\/h3>\r\n<ul>\r\n \t<li>Define surface tension.<\/li>\r\n \t<li>Describe role of intermolecular forces in affecting surface tension.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n<div class=\"textbox examples\">\r\n<h3>Examples<\/h3>\r\n<p id=\"x-ck12-YWZlOGZjZThmZjc2ZTJhODkwYjIwOGI5Y2I3NGVhZTc.-ih9\"><span class=\"x-ck12-img-inline\"><img src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212019\/20140811155423842797.jpeg\" alt=\"This insect is able to stand on water because of surface tension\" width=\"400\" \/><\/span><\/p>\r\n\r\n<h4 id=\"x-ck12-ZWNkMjJhMGUyODBlMzBmZjZjOTQyYzk4NWM5ODQ3ZDA.-jjs_6-frj\">How is this insect able to stand on water?<\/h4>\r\n<p id=\"x-ck12-YjVkZDQ4N2QyMjczN2ZhNzE5NGJkMzQ0MGQ1NWY4M2U.-zhe\">The next time you are by a still body of water, take a close look at what is scooting along on the surface. You may see insects seemingly floating on top of the water. These creatures are known by a variety of names including water skaters, water striders, pond skaters, and other equally descriptive names. They take advantage of a property called surface tension to stay above the water and not sink. The force they exert downward is less than the forces exerted among the water molecules on the surface of the pond, so the insect does not penetrate beneath the surface of the water.<\/p>\r\n\r\n<\/div>\r\n<h3>Surface Tension<\/h3>\r\n<p id=\"x-ck12-ZjljNmI4YWVlNTI3MjFjYTY0N2RmZDQyMTkzYmQwMzY.-vjc\">Molecules within a liquid are pulled equally in all directions by intermolecular forces. However, molecules at the surface are pulled downwards and sideways by other liquid molecules, but not upwards away from the surface. The overall effect is that the surface molecules are pulled into the liquid, creating a surface that is tightened like a film (see A in <strong>Figure <\/strong>below ). The <strong>surface tension <\/strong>of a liquid is a measure of the elastic force in the liquid\u2019s surface. Liquids that have strong intermolecular forces, like the hydrogen bonding in water, exhibit the greatest surface tension. Surface tension allows objects that are denser than water, such as the paper clip shown in B in <strong>Figure <\/strong>below , to nonetheless float on its surface. It is also responsible for the beading up of water droplets on a freshly waxed car because there are no attractions between the polar water molecules and the nonpolar wax.<\/p>\r\n\r\n<div id=\"x-ck12-MzRkNTBjOGFjYjIxMmRhMWM1YWUxN2Y5Y2JmNWM3YzY.-ezx\" class=\"x-ck12-img-postcard x-ck12-nofloat\">\r\n<p id=\"x-ck12-ebo\"><img id=\"x-ck12-OTgwNDUtMTM2MzMyNDA1OC05Ny03OC00LjEuNi4y\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212020\/20140811155424066603.png\" alt=\"Surface tension is created because liquid boundaries lack intramolecular forces\" longdesc=\"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-admin\/(A)%20Molecules%20at%20the%20surface%20of%20a%20liquid%20are%20pulled%20downwards%20into%20the%20liquid%2C%20creating%20a%20tightened%20surface.%20(B)%20Surface%20tension%20allows%20a%20paper%20clip%20to%20float%20on%20water%E2%80%99s%20surface.\" \/><\/p>\r\n<strong>Figure 13.7<\/strong>\r\n<p id=\"x-ck12-NDU0OTQ3NDQ4NmQ0NTdmYzhlMWY4NWYzMzk4NmNjZWY.-ehh\">(A) Molecules at the surface of a liquid are pulled downwards into the liquid, creating a tightened surface. (B) Surface tension allows a paper clip to float on water\u2019s surface.<\/p>\r\n\r\n<\/div>\r\n<p id=\"x-ck12-MTdlMTgzNWU3OGRmY2M1M2IwODM1ZmI4MWU3ZjNlOWM.-yah\">Other liquids, such as diethyl ether, do not demonstrate strong surface tension interactions. The intermolecular forces for the ether are the relatively weak dipole-dipole interactions that do not draw the molecules together as tightly as hydrogen bonds would.<\/p>\r\n<p id=\"x-ck12-YjcxNGMwYTg2NjdlMmY2NWMwMmRmZDI4MGYxNWM1ODY.-qvx\">Watch a short video of water striders in a pond:<\/p>\r\nhttps:\/\/youtu.be\/mCd6zIuACLw\r\n<div class=\"textbox key-takeaways\">\r\n<h3>Summary<\/h3>\r\n<ul id=\"x-ck12-YTZmOWI3YjQzN2Q0YjhhOGQ1NjNhMjZkYWNjYWMzNTQ.-eeo\">\r\n \t<li>The surface tension of a liquid is a measure of the elastic force in the liquid\u2019s surface.<\/li>\r\n \t<li>Liquids with strong intermolecular forces have higher surface tensions than liquids with weaker forces.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<div class=\"textbox exercises\">\r\n<h3>Practice<\/h3>\r\n<p id=\"x-ck12-Y2JlMjQ5M2YzMTNmNmRjMzNmZTI0MTMzYzcwM2IzZmY.-oud\">Use the link below to answer the following questions:<\/p>\r\n<a href=\"http:\/\/sciencing.com\/can-certain-bugs-walk-water-6584563.html\" target=\"_blank\" rel=\"noopener\">http:\/\/sciencing.com\/can-certain-bugs-walk-water-6584563.html<\/a>\r\n<ol id=\"x-ck12-NGIzZjYzOTk2OWE3NTQwNzUxYzk4ODY3NGExMTc2Njg.-zhq\">\r\n \t<li>Do water-walking insects produce a wax that keeps their legs from getting wet?<\/li>\r\n \t<li>What is on these insects legs that helps them walk on water?<\/li>\r\n \t<li>How do other insects keep from sinking in the water?<\/li>\r\n<\/ol>\r\n<\/div>\r\n<div class=\"textbox exercises\">\r\n<h3>Review<\/h3>\r\n<ol id=\"x-ck12-NDdjZjQ1MmQ0Y2JhZTkzNTc5ODc3NWI4NmI1Y2VmYzA.-elw\">\r\n \t<li>Define surface tension.<\/li>\r\n \t<li>What is responsible for the strong surface tension in water?<\/li>\r\n \t<li>Does diethyl ether have a stronger or weaker surface tension than water?<\/li>\r\n<\/ol>\r\n<\/div>\r\n<div class=\"x-ck12-data-problem-set\">\r\n<div class=\"textbox learning-objectives\">\r\n<h3>Glossary<\/h3>\r\n<div class=\"x-ck12-data-vocabulary\">\r\n<ul id=\"x-ck12-ZDRiZmY5NDAyMzljYjE4ZGRjOTE3NTAyNDFhYTU3NjI.-rt1\">\r\n \t<li><strong>surface tension: <\/strong>A measure of the elastic force in the liquid\u2019s surface.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\n[reveal-answer q=\"836080\"]Show References[\/reveal-answer]\r\n[hidden-answer a=\"836080\"]\r\n<h2>References<\/h2>\r\n<ol>\r\n \t<li>Gordon Wrigley. <a href=\"http:\/\/www.flickr.com\/photos\/tolomea\/5510378168\/\">http:\/\/www.flickr.com\/photos\/tolomea\/5510378168\/ <\/a>.<\/li>\r\n \t<li>(A) User:F\u00fcsiahh\/Wikimedia Commons; (B) User:Kaldari\/Wikimedia Commons. (A) http:\/\/commons.wikimedia.org\/wiki\/File:Wassermolek%C3%BCleInTr%C3%B6pfchen-2.svg; (B) http:\/\/commons.wikimedia.org\/wiki\/File:Water_surface_tension_2.jpg .<\/li>\r\n<\/ol>\r\n[\/hidden-answer]","rendered":"<div class=\"x-ck12-data-objectives\">\n<div class=\"textbox learning-objectives\">\n<h3>Learning Objectives<\/h3>\n<ul>\n<li>Define surface tension.<\/li>\n<li>Describe role of intermolecular forces in affecting surface tension.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<div class=\"textbox examples\">\n<h3>Examples<\/h3>\n<p id=\"x-ck12-YWZlOGZjZThmZjc2ZTJhODkwYjIwOGI5Y2I3NGVhZTc.-ih9\"><span class=\"x-ck12-img-inline\"><img decoding=\"async\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212019\/20140811155423842797.jpeg\" alt=\"This insect is able to stand on water because of surface tension\" width=\"400\" \/><\/span><\/p>\n<h4 id=\"x-ck12-ZWNkMjJhMGUyODBlMzBmZjZjOTQyYzk4NWM5ODQ3ZDA.-jjs_6-frj\">How is this insect able to stand on water?<\/h4>\n<p id=\"x-ck12-YjVkZDQ4N2QyMjczN2ZhNzE5NGJkMzQ0MGQ1NWY4M2U.-zhe\">The next time you are by a still body of water, take a close look at what is scooting along on the surface. You may see insects seemingly floating on top of the water. These creatures are known by a variety of names including water skaters, water striders, pond skaters, and other equally descriptive names. They take advantage of a property called surface tension to stay above the water and not sink. The force they exert downward is less than the forces exerted among the water molecules on the surface of the pond, so the insect does not penetrate beneath the surface of the water.<\/p>\n<\/div>\n<h3>Surface Tension<\/h3>\n<p id=\"x-ck12-ZjljNmI4YWVlNTI3MjFjYTY0N2RmZDQyMTkzYmQwMzY.-vjc\">Molecules within a liquid are pulled equally in all directions by intermolecular forces. However, molecules at the surface are pulled downwards and sideways by other liquid molecules, but not upwards away from the surface. The overall effect is that the surface molecules are pulled into the liquid, creating a surface that is tightened like a film (see A in <strong>Figure <\/strong>below ). The <strong>surface tension <\/strong>of a liquid is a measure of the elastic force in the liquid\u2019s surface. Liquids that have strong intermolecular forces, like the hydrogen bonding in water, exhibit the greatest surface tension. Surface tension allows objects that are denser than water, such as the paper clip shown in B in <strong>Figure <\/strong>below , to nonetheless float on its surface. It is also responsible for the beading up of water droplets on a freshly waxed car because there are no attractions between the polar water molecules and the nonpolar wax.<\/p>\n<div id=\"x-ck12-MzRkNTBjOGFjYjIxMmRhMWM1YWUxN2Y5Y2JmNWM3YzY.-ezx\" class=\"x-ck12-img-postcard x-ck12-nofloat\">\n<p id=\"x-ck12-ebo\"><img decoding=\"async\" id=\"x-ck12-OTgwNDUtMTM2MzMyNDA1OC05Ny03OC00LjEuNi4y\" src=\"https:\/\/s3-us-west-2.amazonaws.com\/courses-images-archive-read-only\/wp-content\/uploads\/sites\/53\/2014\/08\/19212020\/20140811155424066603.png\" alt=\"Surface tension is created because liquid boundaries lack intramolecular forces\" longdesc=\"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-admin\/(A)%20Molecules%20at%20the%20surface%20of%20a%20liquid%20are%20pulled%20downwards%20into%20the%20liquid%2C%20creating%20a%20tightened%20surface.%20(B)%20Surface%20tension%20allows%20a%20paper%20clip%20to%20float%20on%20water%E2%80%99s%20surface.\" \/><\/p>\n<p><strong>Figure 13.7<\/strong><\/p>\n<p id=\"x-ck12-NDU0OTQ3NDQ4NmQ0NTdmYzhlMWY4NWYzMzk4NmNjZWY.-ehh\">(A) Molecules at the surface of a liquid are pulled downwards into the liquid, creating a tightened surface. (B) Surface tension allows a paper clip to float on water\u2019s surface.<\/p>\n<\/div>\n<p id=\"x-ck12-MTdlMTgzNWU3OGRmY2M1M2IwODM1ZmI4MWU3ZjNlOWM.-yah\">Other liquids, such as diethyl ether, do not demonstrate strong surface tension interactions. The intermolecular forces for the ether are the relatively weak dipole-dipole interactions that do not draw the molecules together as tightly as hydrogen bonds would.<\/p>\n<p id=\"x-ck12-YjcxNGMwYTg2NjdlMmY2NWMwMmRmZDI4MGYxNWM1ODY.-qvx\">Watch a short video of water striders in a pond:<\/p>\n<p><iframe loading=\"lazy\" id=\"oembed-1\" title=\"They Walk on Water\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/mCd6zIuACLw?feature=oembed&#38;rel=0\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<div class=\"textbox key-takeaways\">\n<h3>Summary<\/h3>\n<ul id=\"x-ck12-YTZmOWI3YjQzN2Q0YjhhOGQ1NjNhMjZkYWNjYWMzNTQ.-eeo\">\n<li>The surface tension of a liquid is a measure of the elastic force in the liquid\u2019s surface.<\/li>\n<li>Liquids with strong intermolecular forces have higher surface tensions than liquids with weaker forces.<\/li>\n<\/ul>\n<\/div>\n<div class=\"textbox exercises\">\n<h3>Practice<\/h3>\n<p id=\"x-ck12-Y2JlMjQ5M2YzMTNmNmRjMzNmZTI0MTMzYzcwM2IzZmY.-oud\">Use the link below to answer the following questions:<\/p>\n<p><a href=\"http:\/\/sciencing.com\/can-certain-bugs-walk-water-6584563.html\" target=\"_blank\" rel=\"noopener\">http:\/\/sciencing.com\/can-certain-bugs-walk-water-6584563.html<\/a><\/p>\n<ol id=\"x-ck12-NGIzZjYzOTk2OWE3NTQwNzUxYzk4ODY3NGExMTc2Njg.-zhq\">\n<li>Do water-walking insects produce a wax that keeps their legs from getting wet?<\/li>\n<li>What is on these insects legs that helps them walk on water?<\/li>\n<li>How do other insects keep from sinking in the water?<\/li>\n<\/ol>\n<\/div>\n<div class=\"textbox exercises\">\n<h3>Review<\/h3>\n<ol id=\"x-ck12-NDdjZjQ1MmQ0Y2JhZTkzNTc5ODc3NWI4NmI1Y2VmYzA.-elw\">\n<li>Define surface tension.<\/li>\n<li>What is responsible for the strong surface tension in water?<\/li>\n<li>Does diethyl ether have a stronger or weaker surface tension than water?<\/li>\n<\/ol>\n<\/div>\n<div class=\"x-ck12-data-problem-set\">\n<div class=\"textbox learning-objectives\">\n<h3>Glossary<\/h3>\n<div class=\"x-ck12-data-vocabulary\">\n<ul id=\"x-ck12-ZDRiZmY5NDAyMzljYjE4ZGRjOTE3NTAyNDFhYTU3NjI.-rt1\">\n<li><strong>surface tension: <\/strong>A measure of the elastic force in the liquid\u2019s surface.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"qa-wrapper\" style=\"display: block\"><span class=\"show-answer collapsed\" style=\"cursor: pointer\" data-target=\"q836080\">Show References<\/span><\/p>\n<div id=\"q836080\" class=\"hidden-answer\" style=\"display: none\">\n<h2>References<\/h2>\n<ol>\n<li>Gordon Wrigley. <a href=\"http:\/\/www.flickr.com\/photos\/tolomea\/5510378168\/\">http:\/\/www.flickr.com\/photos\/tolomea\/5510378168\/ <\/a>.<\/li>\n<li>(A) User:F\u00fcsiahh\/Wikimedia Commons; (B) User:Kaldari\/Wikimedia Commons. (A) http:\/\/commons.wikimedia.org\/wiki\/File:Wassermolek%C3%BCleInTr%C3%B6pfchen-2.svg; (B) http:\/\/commons.wikimedia.org\/wiki\/File:Water_surface_tension_2.jpg .<\/li>\n<\/ol>\n<\/div>\n<\/div>\n","protected":false},"author":1507,"menu_order":8,"template":"","meta":{"_candela_citation":"[]","CANDELA_OUTCOMES_GUID":"","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-2592","chapter","type-chapter","status-publish","hentry"],"part":2334,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters\/2592","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/users\/1507"}],"version-history":[{"count":8,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters\/2592\/revisions"}],"predecessor-version":[{"id":3602,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters\/2592\/revisions\/3602"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/parts\/2334"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapters\/2592\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/media?parent=2592"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/pressbooks\/v2\/chapter-type?post=2592"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/contributor?post=2592"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/umes-cheminter\/wp-json\/wp\/v2\/license?post=2592"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}