Chapter 2 Flashcards
Which 4 elements make up 96% of matter in living organisms?
carbon, hydrogen, nitrogen and oxygen
covalent bond
sharing a pair of electrons by two atoms
ionic bond
one atom completely pulls electrons away from the other atom, highly different electronegativities
electronegativity
an atoms attraction for the electrons in a covalent bond
nonpolar covalent bond
bond held by atoms the share the electrons equally, similar electronegativities
polar covalent bond
bond held by atoms that share the electrons unequally, very different electronegativities
What kind of bonds cause partial charges within molecules?
polar covalent bond
hydrogen bonds
attraction of the partial charges on water molecules, - hydrogen -> + oxygen
cohesive behavior
the tendency of water molecules to stick to one another
adhesion
the tendency of water molecules to form hydrogen bonds with other molecules
What causes surface tension?
cohesion between water molecules
surface tension
a measure of how hard it is to break the surface of a liquid
expansion upon freezing
as water freezes into ice, it forms a relatively open crystal structure, making it less dense than liquid water
temperature moderation
water resists changing temperature because it has a high specific heat
specific heat
the amount of energy needed to raise the temperature of 1 g of a substance 1 degree C
