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Atom
Atomic model
Masses of atoms
Periodic table
100
The positively charged center of the atom.
What is the nucleus
100
created first idea that atom make up all substances.
Who is Democritus
100
the unit of measurement used for atomic particales.
What is atomic mass unit
100
searched for a way to organize the elements
Who is Dimitri Mendeleev
200
Particals with an electrictalcharge of 1+
What is a proton
200
he believed that matter was uniform throughout and was not composed of smaller particles.
Who is Aristotle
200
the mass of a proton or a neutron
What is 1 amu
200
vertical column the periodic table
What is a group
300
Neutral particals that do not have an electrictal charge.
What is a nuetron
300
first person to offer proof that atoms exist.
Who is John Dalton
300
1,836 times larger
What is the size relation between protons and neutrons to electrons
300
are added to each element as you go across a period in the periodic table
What is one proton and one electron
400
partical with an electrictal charge of 1-
What is an electron
400
Dalton's first model of an atom.
What is a sphere
400
sum of the number of protons and neutrons in an atom
What is mass number
400
can hold eight electrons
What is energy level 2
500
protons and neutrons made up of smaller particals.
What is a Quark
500
hypothesized that electrons travel in fixed orbit around atom's nucleus.
Who is Niels Bohr
500
the mass of a proton compared to a neutron
What is identical
500
horizontal rows of elements on the periodic table
What is period