Chem

Front 1

Aristotle

Continuous theory of matter

Back 1

matter can be subdivided

Front 2

Democritus

Discontinuous theory of matter

Back 2

get to a point where you can not further divide; "atomus"- indivisible

Front 3

John Dalton

Law of multiple proportion, law of definite proportion, amd law of conservation of mass

Back 3

1. all atoms of the same element are identical
2. atoms of different elements have different properties
3. each element is composed of indivisible particles called atoms
4. whole atoms combine in a definite ratio and in a different arrangement to form compounds
5. atoms are indestructable - can't be created or destroyed

Front 4

atom

Back 4

smallest particle of an element that retains the properties of the element and can exist by itself or in combination with something else

Front 5

electron

Back 5

first subatomical particle discovered; never changed no matter the metal used in cathode ray tube experiment - fundamental particle

Front 6

JJ Thompson

electon: cathode-ray tube

Back 6

identified the electron in 1897

Front 7

Robert Milikan

oil drop experiment

Back 7

led to charge and mass of the electron

Front 8

JJ Thompson

proton

Back 8

discovered in 1899; always a multiple of what Hydrogen was

Front 9

James Chadwick

neutron

Back 9

discovered by accident; harder to discover because of neutral charge

Front 10

nucleus

Back 10

positive charge, 99.9% of the mass, very small radius, highly dense

Front 11

atomic number

Back 11

Z : number of protons in an atom
(bottom left subscript)

Front 12

Mass number

Back 12

A; A = Z + N
-# of neutrons

(top left superscript)

Front 13

Atomic mass

Back 13

actual mass of the atom;

Front 14

Isotopes

Back 14

nuclides of same element - same Z, diff N

Front 15

Isobar

Back 15

same A, Diff Z

Front 16

Isotone

Back 16

same N, diff Z

Front 17

Isoelectronic

Back 17

particles with the same number of electrons

Front 18

atomic weight

Back 18

average of the atomic masses of the natural isotopes of an element based upon the proportion that are found in nature

Front 19

thermal emission

Back 19

when the electrons are emitted by some metals when the metals are heated to a high temperature

Front 20

photoelectric effect

Einstein

Back 20

light can behave as a particle and a wave; when elctrons are emitted from metals when they are exposed to light

Front 21

radioactivity

Back 21

the spntaneous decay of atoms of certain elements into other elements with the simultaneous production of rays or particels

Front 22

alpha particle

Back 22

helium nucleus, positive, most massive, least penitrative power

Front 23

beta particle

Back 23

an electron, negative, little mass, more penitrating

Front 24

gamma rays

Back 24

high energy electromagnetic radiation, no mass, travels at the speed of light, most penitrative

Front 25

nuclear reactions

Back 25

change in nucleus producing diff elements, diff isotopes have diff behavior, rate is unaffected by change in temp,etc, atom is essentially the same regardless if it is in a compound of by itself, great change in energy

Front 26

chemical reactions

Back 26

change in the distribution of the outer energy level electrons, diff isotopes have same behavior, rate is changed, less energy

Front 27

fission

Back 27

break up of a heavy nucleui into smaller ones

Front 28

fussion

Back 28

take lighter particles and make heavier

Front 29

nuclear transmutation

Back 29

process of converting one element to another

Front 30

beta emission

Back 30

wants to decrease ratio of n/p

Front 31

alpha emission

Back 31

increase n/p; add helium to product

Front 32

beta capture

Back 32

bombard nucleus with a beta particle; hydrogen atom to reactants

Front 33

binding energy

Back 33

energy that binds the nucleus together

Front 34

John Dalton

model

Back 34

atom is a hard, little, sphere that is indivisible

Front 35

JJ Thompson

"Raisin pudding model"

Back 35

electrons and protons embedded thru out the atom like raisins in pudding

Front 36

Rutherford

Alpha Particle Scattering Experiment

Back 36

lead to the discovery of the nucleus

Front 37

Bohr

Solar System model

Back 37

electron is moving around the nucleus in an orbit like planets

Front 38

Bohr's 4 postulates

Back 38

1. The e- are located in orbits (energy levels) around the nucleus. As long as it stays in a given orbit, it neither gains nor loses energy.
2. The e- in orbits closest to the nucleus are of lower energy.
3. Every e- in an atom may have only certain allowed energies.
4. The e- can move from one orbit to another. To do this, an e- must gain or lose a certain exact amount of energy

Front 39

Planck

wave mechanical model

Back 39

when light is emitted, it is radiated in quanta, the amount of E radiated can be revealed by the wavelength of the light emitted

Front 40

light spectrum

Back 40

gamma, x-rays, ultraviolet, light, infared rays, microwaves, radar, tv, radio waves

Front 41

DeBroglie

Duality Nature of the electron

Back 41

light can behave like wave and particle

Front 42

Heisenberg

uncertainity principle

Back 42

impossible to know the exact position and momentum of a particle at a given time