Chapter 3

Calorie

Amount of energy needed to raise temperature 1 gram of water 1 degree C.

Adhesion

An attraction between molecules of different substances.

Many of water's emergent properties, such as its cohesion, its high specific heat, and its high heat of vaporization, result from the fact that water molecules _____.

Are attracted to each other by partial negative and positive charges on the oxygen and hydrogen atoms, respectively

What are the four emergent properties of water?

- Cohesion - Temperature Moderation - Floating of Ice - Solvent of life

A pH of 6 is how many times more acidic than a pH of 9?

1,000

Kilocalorie

1000 calories

Heat

A form of energy that is transferred by a difference in temperature. The total amount of Kinetic Energy.

The slight negative charge at one end of one water molecule is attracted to the slight positive charge of another water molecule. What is this attraction called?

A hydrogen bond

Surface Tension

A measure of how difficult it is to stretch or break the surface of a liquid. Water has a high surface tension because of the hydrogen bonding of surface molecules.

Temperature

A measure of how hot or cold something is.

Celsius Scale

A temperature scale that defines the freezing point of water as 0 degrees and the boiling point of water as 100 degrees.

Hydrogen Bonds

A type of weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule.

Cohesion

Attraction between molecules of the same substance.

Kinetic Energy

Energy of motion.

Water molecules have a polarity, which allows them to be electrically attracted to other water molecules and other polar molecules by weak chemical bonds known as _____.

Hydrogen Bonds

Polar Molecule

Molecule with an unequal distribution of charge, resulting in the molecule having a positive end and a negative end

In a water molecule, what charge does the oxygen have?

Negative

In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by:

Polar covalent bonds

In a water molecule, what charge does the hydrogen have?

Positive

Why is there a partial negative charge in a water molecule?

The electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus.

Polar Covalent Bonds

Unequal sharing of electrons

Moderation of Temperature by Water

Water absorbs heat from warm air and releases stored heat to cooler air; has high specific heat; can absorb or release large amount of heat with only slight changes to its own temperature-resists changes to temperature.