1.1 Structure of Water

what type of molecule is water

POLAR

-one end of the molecule is slightly positive while the other end is slightly negative

what bonds are form a water molecule

polar covalent bonding

-covalent=electrons shared

describe hydrogen bonding

the negative oxygen end of one water molecules is attracted to the positive hydrogen end of another water molecule

waters high specific heat means…

water resists temperature change

-result of hydrogen bonds

reasons why waters high specific heat is important

1. large bodies of water temp. remains relatively constant -moderate temp. in coastal areas

2. favorable environment for marine life -organisms made primarily up of water resist changes in their own temp.

how does water react when it is hot outside

water absorbs the heat -hydrogen bonds must be broken

how does water react when it is cold outside

water releases heat -hydrogen bonds form between slower moving water molecules

waters heat of vaporization (liquid to gas)

water has high heat of vaporization -result of hydrogen bonds-must break before water can evaporate

waters evaporative cooling

high energy molecules leave liquid phase —> reduces average kinetic energy —> lowers temp. of remaining liquid

how does waters evaporative cooling help environment

1.Keeps bodies of water from evaporating

2.Organisms regulate body temp. (sweating)

cohesion

tendency of molecules to stick together because of hydrogen bonds water——-water

adhesion

hydrogen bonding between water and molecules of diff. substances water—different substance

surface tension

how difficult it is to break the surface of a liquid -water has high surface tension

why is water as a solid less dense than its liquid form

water freezes —→ hydrogen bonds stabilize, molecules spread apart—→ crystal lattice

how does water being less dense in solid form benefit organisms

1. life can exist under the frozen surfaces

2. when hydrogen bonds form, it releases heat and helps insulate the water beneath the ice