Water molecules are very polar: * The oxygen atom attracts its shared electrons strongly, so the oxygen atom has a slightly negative charge. * The hydrogen has a slightly positive charge. * This makes them “stick” to each other with a strong attraction called a hydrogen bond . Name: _________________ O H H hydrogen bond O H Water has a high specific heat: * High specific heat means it takes a LOT of energy to change a body of water’s temperature . * Aquatic life can live without rapid/deadly changes in temperature . H O H H Pr perties f Water Ice is less dense than water: * Ice forms at the top of water because of the cold air. Aquatic organisms that live underneath the ice in the water are insulated from extreme cold by the ice. * This also allows for some animals to live on top of the ice! Capillary Action: * Water moves up thin tubes within plants! * Water is drawn up the tube, against gravity , by the forces of cohesion and adhesion . adhesion cohesion water © Bethany Lau Water has a strong surface tension: * Molecules at the surface hold more tightly to each other than molecules further under the surface. * Some life depends on being able to float on top of the surface. * This is also why water can bead up into droplets on glass surfaces . H H O Water is a terrific solvent: * Many ions and polar molecules necessary for life can dissolve in water. * Water is great for carrying these ions and molecules within cells or blood vessels between different body tissues. H O O H H H H H O H H O O H H H O H H H O O O O H H H H H H O H O H H H H H H H O O H O H O O O H H H H H H - H H H + O O O O H H O H O H H H - H + O H H H H H H O H O H H O H Imp rtant f r Life Water has a relatively high boiling point and heat of vaporization for a small hydride molecule: * It takes a lot of heat energy for water molecules to leave their liquid form , held together by hydrogen bonds. * Because water does not boil at a lower temperature, most water on the planet is found in the form of liquid , which is essential for life! * Surface water molecules can evaporate when individually they gain enough energy to break free from the hydrogen bonds of the molecules around them. H H H O O H H O H H O H O H H O O H H H O O H H H O H H H H O H O H H H O H H H H H enough heat energy surface molecule O H H O H Is there water on other planets? * Many moons in our solar system have evidence of ice and perhaps liquid water is underneath. * Scientists believe liquid water is a requirement for life to exist, which is why we keep looking for it! * Most planets are too hot or too cold for liquid water to exist. © Bethany Lau Water molecules are very polar: * The oxygen atom attracts its shared electrons strongly, so the oxygen atom has a slightly charge. * The hydrogen has a slightly charge. * This makes them “stick” to each other with a strong attraction called a . Name: _________________ O H H hydrogen bond O H Water has a high specific heat: * High specific heat means it takes of energy to change a body of water’s . * Aquatic life can live without rapid/deadly changes in . H O H H Pr perties f Water Ice is less dense than water: * Ice forms at the because of the cold air. Aquatic organisms that live underneath the ice in the water are from extreme cold by the ice. * This also allows for some animals to live on top of the ice! Capillary Action: * Water moves up tubes within plants! * Water is drawn up the tube, against , by the forces of and . adhesion cohesion water © Bethany Lau Water has a strong surface tension: * Molecules at the surface hold to each other than molecules further under the surface. * Some life depends on being able to float on top of the surface. * This is also why water can bead up into droplets on glass surfaces . H H O Water is a terrific solvent: * Many ions and polar molecules necessary for life in water. * Water is great for carrying these ions and molecules within or between different body tissues. H O O H H H H H O H H O O H H H O H H H O O O O H H H H H H O H O H H H H H H H O O H O H O O O H H H H H H - H H H + O O O O H H O H O H H H - H + O H H H H H H O H O H H O H Imp rtant f r Life Water has a relatively high boiling point and heat of vaporization for a small hydride molecule: * It takes a lot of heat energy for water molecules to leave their , held together by . * Because water does not boil at a lower temperature, most water on the planet is found in the form of , which is essential for life! * Surface water molecules can evaporate when individually they gain enough to break free from the of the molecules around them. H H H O O H H O H H O H O H H O O H H H O O H H H O H H H H O H O H H H O H H H H H enough heat energy surface molecule O H H O H Is there water on other planets? * Many in our solar system have evidence of ice and perhaps liquid water is underneath. * Scientists believe is a requirement for life to exist, which is why we keep looking for it! * Most planets are or for liquid water to exist. © Bethany Lau