You can also purchase this book at Amazon. Water molecule. Bionote To avoid the pain of a belly-flop, divers enter the water with their hands or feet first to break the surface tension of water. See also:. Trending Here are the facts and trivia that people are buzzing about. Is Vatican City a Country? The Languages of Africa.
The Mongol Empire. The Most and Least Religious Countries. Key Takeaways Key Points The difference in electronegativities between oxygen and hydrogen atoms creates partial negative and positive charges, respectively, on the atoms. Water molecules attract or are attracted to other polar molecules. Molecules that do not dissolve in water are known as hydrophobic water fearing molecules.
Key Terms hydrophilic : having an affinity for water; able to absorb, or be wetted by water hydrophobic : lacking an affinity for water; unable to absorb, or be wetted by water polarity : The intermolecular forces between the slightly positively-charged end of one molecule to the negative end of another or the same molecule.
Key Takeaways Key Points As water is boiled, kinetic energy causes the hydrogen bonds to break completely and allows water molecules to escape into the air as gas steam or water vapor.
When water freezes, water molecules form a crystalline structure maintained by hydrogen bonding. Solid water, or ice, is less dense than liquid water. Ice is less dense than water because the orientation of hydrogen bonds causes molecules to push farther apart, which lowers the density. For other liquids, solidification when the temperature drops includes the lowering of kinetic energy, which allows molecules to pack more tightly and makes the solid denser than its liquid form.
Because ice is less dense than water, it is able to float at the surface of water. Key Terms density : A measure of the amount of matter contained by a given volume. Key Takeaways Key Points Water has the highest heat capacity of all liquids.
Oceans cool slower than the land due to the high heat capacity of water. To change the temperature of 1 gram of water by 1 degree Celsius, it takes 1. Key Terms heat capacity : The capability of a substance to absorb heat energy specific heat : the amount of heat, in calories, needed to raise the temperature of 1 gram of water by 1 degree Celsius. Learning Objectives Explain how heat of vaporization is related to the boiling point of water.
Key Takeaways Key Points The dissociation of liquid water molecules, which changes the substance to a gas, requires a lot of energy. The boiling point of water is the temperature in which there is enough energy to break the hydrogen bonds between water molecules.
Water is converted from its liquid form to its gaseous form steam when the heat of vaporization is reached. Evaporation of sweat mostly water removes heat from the surface of skin, cooling the body.
Key Terms heat of vaporization : The energy required to transform a given quantity of a substance from a liquid into a gas at a given pressure often atmospheric pressure. Learning Objectives Explain why some molecules do not dissolve in water. Key Takeaways Key Points Water dissociates salts by separating the cations and anions and forming new interactions between the water and ions. Water dissolves many biomolecules, because they are polar and therefore hydrophilic.
Key Terms dissociation : The process by which a compound or complex body breaks up into simpler constituents such as atoms or ions, usually reversibly. Learning Objectives Describe the cohesive and adhesive properties of water. Key Takeaways Key Points Cohesion holds hydrogen bonds together to create surface tension on water.
Since water is attracted to other molecules, adhesive forces pull the water toward other molecules. Water is transported in plants through both cohesive and adhesive forces; these forces pull water and the dissolved minerals from the roots to the leaves and other parts of the plant.
Key Terms adhesion : The ability of a substance to stick to an unlike substance; attraction between unlike molecules cohesion : Various intermolecular forces that hold solids and liquids together; attraction between like molecules.
Learning Objectives Explain the composition of buffer solutions and how they maintain a steady pH. Key Terms alkaline : having a pH greater than 7; basic acidic : having a pH less than 7 buffer : a solution composed of a weak acid and its conjugate base that can be used to stabilize the pH of a solution. Licenses and Attributions. CC licensed content, Shared previously. Key Terms hydrophilic : having an affinity for water; able to absorb, or be wetted by water hydrophobic : lacking an affinity for water; unable to absorb, or be wetted by water polarity : The intermolecular forces between the slightly positively-charged end of one molecule to the negative end of another or the same molecule.
As this macro image of oil and water shows, oil does not dissolve in water but forms droplets instead. This is due to it being a nonpolar compound. For example, in Denver, CO 5, ft. On Mount Everest in Nepal 29, ft. Home Science Tools offers a wide variety of earth science products and kits.
Find earth science products and space educational supplies for labs and classrooms. To get started with our leaf chromatography experiment, we first must learn about leaves. Leaves contain different pigments, which give them their color. Green chlorophyll is the most common type of pigment, but there are also carotenoids yellow, orange and Discover the colors behind the colors of popular candies with a Candy Chromatography Science Project.
First you'll learn what chromatography means. Then you'll use a candy chromatography science experiment to test two types of candy. Find out if there are other colors Debbie helped her husband Frank start Home Science Tools back in
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