Foundations of Biology Chapter Two

isotopes

atoms with different numbers of neutrons

valence electrons

in the atoms outermost level- determines most of the atoms behavior

covalent bond

sharing of electrons

non polar

the electrons are shared equally

polar

the electrons are being pulled to one side

ionic bond

a transfer of electrons (charged)

cation

positive

anion

negative

molecule

2 or more atoms joined together

molecule

2 or more atoms joined together

hydrogen bond

attraction between a slightly positive hydrogen in one and slightly negative atom in another molecule

reactants

items that join together - written to the left

products

what gets made - written to the right of an arrow

Adhesion

clinging of different molecules

cohesion

linking of like molecules to each other

high specific heat

water can absorb a lot of heat before changing temperature

high heat of vaporization

amount of heat required to turn liquid water into gas

acids

compounds that RELEASE H+

bases

compounds that JOIN H+

pH

a logarithmic measure of the amount of H+

buffer

compound that maintains a stable pH - protects us

Polar molecules have?

An uneven distribution of charges

The electrons are shared equally in a?

Non polar covalent bond

Where is the energy molecule ATP made in a cell

Mitochondria

What does the atomic number tell us about an atom?

the number of protons and number of electrons