Chem One: Chapter Three-One

Front 1

law of conservation of mass

Back 1

mass is neither created nor destroyed during ordinary chemical or physical reactions but it can change form

Front 2

law of definite proportions

Back 2

a chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the sample or the source of the compound.

Front 3

law of multiple proportions

Back 3

if two or more different compounds are composed of the same two elements, then the ratio of the masses of the second element combined with a certain mass of the first element is always a ratio of small whole numbers

Front 4

daltons atomic theory

Back 4

all matter is composed of extremely small particles called atoms; atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass, and other properties; atoms cannot be subdivided, created or destroyed, atoms of different elements combine in simple whole number ratios to form chemical compounds, in chemical reactions, atoms are combined, separated or rearranged.

Front 5

modern atomic theory

Back 5

all matter is composed of atoms; atoms of any one element differ in properties from atoms of another element remain unchanged.

Front 6

Democritus

Back 6

Universe is made up of tiny indivisible atoms

Front 7

Aristotle

Back 7

Matter was continuous and could be decided forever

Front 8

Atoms

Back 8

the smallest particle of an element that retains the chemical properties of that element; made up of protons, neutrons, and electons

Front 9

JJ Thompson

Back 9

Discovered electrons through the cathode ray

Front 10

Robert Millikan

Back 10

used oil drop experiment to confirm the negative charge of electrons and small mass

Front 11

Ernest Rutherford

Back 11

Shot alpha particles to discover the small and dense nucleus

Front 12

strong nuclear forces

Back 12

the forces in the nucles which hold particles together;proton-proton; proton-neutron; neutron-neutron

Front 13

atomic number

Back 13

equal to the number of protons; different elements have different these.

Front 14

isotopes

Back 14

varying number of neutrons in an element; changes the atomic mass

Front 15

hydrogens isotopes

Back 15

protium, deuterium; tritium

Front 16

Hyphen Method

Back 16

element name, hyphen, atomic mass

Front 17

Nuclear symbol method

Back 17

atomic mass
element symbol
atomic number

Front 18

average atomic mass

Back 18

the weighted average of the atomic masses of the naturally occuring isotopes of an element

Front 19

Avagadros number

Back 19

number of particles in one mole of carbon

Front 20

mole

Back 20

the amount of a substane that contains as many particcles as there are atoms in exactly 12 grams of carbon

Front 21

molar mass

Back 21

the mass of one mole of a pure substance eguals ann elements atomic mass rounded to two decimal places