Study Set Content:
An explanation of the structure of matter in terms of different combination of very small particles
Atomic Theory
extremely small particle
Atom
Type of matter composed of only one kind of atom
Element
Consists of 2 or more elements
Compound
“the ratio mass for the same compound
is constant”
Law of definite proportions
“the ratio mass for the same compound
is constant”
Law of definite proportions
“the ratio mass for the same compound
is constant”
Law of definite proportions
made the law of constant/definite proportions
Joseph Proust
multiple elements can combine with
each other in multiple ratios”
Law of multiple proportions
“The same amount of matter exists
before and after the change—none is
created or destroyed”
Law of Conservation of Mass
a dense central core within the atom
Nucleus
Positively charged particle
Proton
Negatively charged particle
electron
negatively charged particle
electron
electrically neutral particle
Neutron
Who discovered the electron
Joseph John Thomson
Determined the charge of an electron
Robert Andrews Millikan
Discovered the protons and nucleus
Ernest Rutherford
Discovered neutrons
James Chadwick
average mass is equal to
fractional abundance x isotopic mass
