Chem H

me

matter

solid, liquid, gas

element

a substance that cannot be broken down to other substances

atom

smallest unit of matter that still retains properties of an element

proton

single positive charge

electron

single negative charge

neutro

electrically neutral

atomic number

number of protons in an atom (makes the atoms of one element different from atoms of another element——-same number of electrons)

mass number

number of protons+neutrons

valence shell

outermost shell of an atom, 2 8 8, determines chemical properties

isotopes

different number of neutrons

compound

a substance consisting of two or more different elements in a fixed ratio

DNA

hydrogen bond, contains carbon, hydrogen, oxygen, and nitrogen

ion

an atom that has a positive or negative charge because of an unequal amount of protons and neutrons

cation

positive

anion

negative

chemical bonds

the results in attractions between atoms, ionic, covalent, hydrogen

ionic bond

attraction between a cation and anion

covalent bond

atoms share outer shell electrons

nonpolar (covalent)

2 atoms of the same element share electrons EQUALLY

same element

carbon and hydrogen

polar (covalent)

compete for shared electrons, UNEQUAL sharing

electronegativity

the pull/attraction of an atom, more electronegativity means pull harder

polar molecules

molecules with unequal distribution of charges

h2o

oxygen slight negative

hydrogen slight positive

hydrogen bonds

weakest, cannot form a com-pound

the positively charged region is ALWAYS hydrogen, therefore called hydrogen bond

Organic compounds

have carbon in structure

carbohydrates, protiens, lipids, nucleic acids

inorganic compounds

water, acid, base, salts

cohesion

hydrogen bonding causes molecules to stick together

much stronger for water than other liquids

(plants)

surface tension

how difficult it is to break the surface of a liquid (hydrogen bonds)

adhesion

the tendency of water to stick to other substances (covalent bond?)

heat

must be absorbed to break hydrogen bonds

is released when they form

water resists temperature changes

ice

less dense than liquid water (floats)

solution

a liquid consisting of a uniform mixture of 2 or more substances

solvent

dissolving agent

solute

substance that is dissolved

acids

dissociate into H+ and one or more anions (negative)

bases

dissociate into OH- (hydroxide) and one or more cations

salts

dissociate into anions and cations, none are H+ or OH-

pH

potential of hydrogen, describes if a solution is acidic or basic (0[most acidic] to 14 [most basic])

chemical reactions

reactants→products