History of the Atom
Elements
Periodic Table
Periodic Table part 2
Electrons
100
He named the atom after a Greek word that means " uncut"
who is Democritus
100
Smallest particle of an element that has all the properties of that element.
What is an atom?
100
First person to create a periodic table - he arranged the element in order of increasing mass.
Who is Mendeleev?
100
Represents the number of protons an atom has.
What is the atomic number?
100
He believed that electrons moved in orbits at fixed distances from the nucleus.
Who is Bohr?
200
He thought all substances were built up from only four elements - earth, air, fire, and water.
Who is Aristotle?
200
Subatomic particle with a positive charge, found in the nucleus of an atom
What is a proton?
200
element on the periodic table are arranged by this.
What is increasing atomic number?
200
Equals the number of protons plus the number of neutrons in an atom.
What is the mass number?
200
energy levels
What are the possible energies that electrons can have?
300
He proposed the theory that all matter is made up of individual particles, called atoms, that cannot be divided.
Who is Dalton?
300
Subatomic particle found in the nucleus with no charge.
What is a neutron?
300
A row of elements in the periodic table.
What is a period?
300
Can be used to figure the number of electrons in an atom.
What is the atomic number?
300
By gaining or losing energy.
How does an electron move from one energy level to another?
400
His theory is called the "plum pudding" model.
Who is Thomson?
400
Region around the nucleus of an atom occupied by electrons.
What is an electron cloud?
400
Each column of elements in the periodic table.
What is a group?
400
Metals, nonmetals, metalloids
How are elements classified?
400
A region of space around the nucleus where electrons are likely to be found.
What is an orbital?
500
He proposed that all of an atom's positive charge is concentrated in its nucleus.
Who is Rutherford?
500
Atoms of an element that have the same number of protons, but a different number of neutrons.
What is an isotope?
500
This is often a one or two letter abbreviation.
What is a chemical symbol?
500
elements that are good conductors of heat and electricity
What are metals?
500
Ground state.
What is when all electrons in an atom have the lowest possible energies?
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