Water (2.2)

Covalent bonds

Because oxygen wants electrons so badly, it tugs electrons toward it in an unequal sharing of electrons. This gives O a negative charge and H a positive charge. (polar covalent bond)

Hydrogen bonds are weak intermolecular forces, which give water its unique properties.

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this forms from the uneven sharing of electrons

They form when the negatively charged oxygen on one molecule is electrostatically attracted to the positive hydrogen on another

Cohesive, adhesive, thermal, and solvent

Having different charges in one molecule

Cohesion refers to the binding of 2 molecules of the same type

Water coheres because of hydrogen bonds

The evaporative loss of water from plant leaves

Adhesion refers to the binding of water to another polar molecule

the ability for a liquid to flow through narrow spaces without the assistance of gravity

• it allows water to be transported to the top of trees through xylem vessels

• in leaves, water adheres to cellulose in the cell wall f leaves • aids in drawing water up during capillary action

high specific heat capacity, high heat of vaporization, water as a coolant, and high boiling point

H-bonds restrict water’s movement, which causes water to need a large amount of energy to change temperature. Water can absorb or lose great amounts of energy while keeping a stable temperature.

• aquatic organisms can maintain homeostasis due to the stable temperatures of water.

Water needs a large amount of energy to evaporate because H-bonds need to be broken.

Evaporation has a cooling effect. When a molecule evaporates, it takes a small amount of heat with it.

• evaporating sweat helps humans maintain a steady body temperature.

100 C and 0 C. This is the temperature range for most organisms on Earth

Many different substances can dissolve in water because of it’s polarity (ex. Na and glucose)