Studied by 31 people
proton charge
positive
electron charge
negative
neutron charge
neutral
atom
building blocks of matter
nucleus
the center of an atom where protons and neutrons are located
energy levles
areas outside of the nucleus occupied by electrons
valence electrons
outermost electrons that determine the reactivity of an atom
element
a pure substance that cannot be broken down
atomic number
the number of protons in the nucleus of an atom
mass number
the number of protons and neutrons
atomic weight
average amount of neutrons in an element
period
horizontal rows on the periodic table
group
vertical columns on the periodic table
isotope
atoms of the same element that have the same number of protons and electrons but have a different number of neutrons
radioactive isotope
isotopes that give off radiation
compound
a pure substance formed when two or more different elements combine
covalent bond
the chemical bond that forms when electrons are shared
molecule
a compound in which the atoms are held together by covalent bonds
ion
an atom that has lost or gained one or more electrons
ionic bond
an electrical attraction between two oppositely charged atoms
van der Waals forces
attractions between molecules
chemical reaction
the process by which atoms or groups of atoms in substances are recognized into different substances
reactant
starting substances to the left of the arrow
product
formed substances to the right of the arrow
Activation energy
the minimum amount of energy needed for reactants to form products
catalyst
substances that lowers the activation energy needed to start a chemical reaction
enzyme
a substance produced by a living organism which acts as a catalyst
polar molecules
molecules that have an uneven distribution of charge
hydrogen bond
a weak interaction involving hydrogen atoms and a fluorine, oxygen, or nitrogen atom
mixture
combination with two or more substances that don’t create a chemical reaction
homogeneous mixture
a uniform mixture
solvent
able to dissolve other substances (water)
solute
substance that dissolves
heterogeneous mixture
a mixture with distinctive substances
suspension
a type of heterogeneous mixture where the particles settle out overtime
acid
substance that releases H+ ions when they dissolve
base
substance that releases OH- ions when they dissolve
pH
the measure of concentration of H+ in a solution
macromolecules
large molecules that are formed by joining smaller organic molecules together
polymer
molecules made from repeating units of identical or nearly identical compounds called monomers
carbohydrate
compounds composed of a ratio of 1 carbon :2 hydrogen :1 oxygen
lipid
molecules made mostly of carbon and hydrogen that make up the fats, oils, and waxes
proteins
compounds made of smaller carbon compounds called amino acids
nucleic acids
complex macromolecules that transmit and store genetic information
Note 
Flashcard (54)