Chemistry Chapter 4

Front 1

Democritus

Back 1

Greek philosopher, first person to propose the idea that matter was not infinitely divisible

Front 2

Aristotle

Back 2

influention in the rejection of the concept of the atom

Front 3

John Dalton

Back 3

Atomic theory was a breakthrough in our understanding of matter

Front 4

atom

Back 4

smallest particle of an element that retains the properties of the element

Front 5

cathode ray

Back 5

ray of radiation, originated from the cathode end of the tube. Stream of charged particles

Front 6

electrion

Back 6

negatively charged particles

Front 7

nucleus

Back 7

centrally located within the atom that contained all of an atom's positive charge and virtually all of its mass

Front 8

proton

Back 8

subatomic particle carrying a charge equal to but opposite that of an electron, positive charge of +1

Front 9

neutron

Back 9

has a mass nearly equal to that of a proton, but it carries no electrical charge

Front 10

J.J. Thomson

Back 10

identified the first subatomic particle-the electron

Front 11

building blocks of all atoms

Back 11

electrons, protons nucleus (all the mass of an atom

Front 12

Rutherford

Back 12

The Nuclear Atom (tiny, dense region centrally located within an atom that contains all of an atoms positive charge f virtually all of its mass.

Front 13

Nuclear Reaction

Back 13

reaction involving an atom of one element changing into an atom of another element

Front 14

Radioactivity

Back 14

the spontaneous emission of radiation by by some substances

Front 15

Radiation

Back 15

rays and particles emitted by the radioactive Material

Front 16

Radioactive decay

Back 16

process that doesn't require energy but allows unstable nuclei to lose energy by emitting radiation spontaneously

Front 17

subscript

Back 17

number of protons

Front 18

superscript

Back 18

Mass Number