chemistry of life part 1

element

substance that cannot be broken down into smaller parts

compound

a substance formed when atoms from two or more different chemical elements are chemically bonded together

atomic number

the number of protons an element contains, determines hte identity of an element

isotopes

elements with the same number of protons but different numbers of neutrons

valence shell

the outer energy shell, determines how it will combine with other molecules

covalent bond

may be nonpolar or polar

ionic bond

result from attraction of oppositely charged ions

hydrogen bond

a weak attraction that forms between a partially positive hydrogen atom in one molecule and a partially negative electronegative atom

van der walls forces/interactions

weak, short-range, attractive forces that arise from temporary fluctuations in electron distribution within molecules, leading to transient dipoles that attract other molecules

specific heat

the amount of heat needed to raise the temp of one unit of mass by one degree of c

evaporative cooling

water evaporation removes heat from surface

heat of vaporization

amount of energy needed to change the substance from liquid to gas

hydrophobic

hates water

hydrophilic

likes water

solution

solute is dissolved in solvent

solvent

dissolves the solute

solute

substance that dissolves

acid

ph below 7

base

ph above 7

pH

a scale used to measure how acidic or basic an element is

valence electrons

valence number/valency

capillary action

ice floats

universal solvent