Theory of an Atom
In an atom, electrons move in definite orbits around the nucleus.
Bohr
Who stated that atoms cannot be divided?
Dalton
Place the following scientists in order, from earliest to latest: Rutherford, Dalton, Bohr, Thomson
Dalton, Thomson, Rutherford, Bohr
The first person to propose a theory about an atom called the Atomos Theory was
Democritus
How did each model of the atom help to develop the atomic theory?
Each model built upon the other to show new particles or properties of previously discovered particles.
Subatomic particles with a negative charge
Electrons
What subatomic particle(s) would be found orbiting the nucleus?
Electrons only
Who discovered the nucleus using the gold foil experiment?
Ernest Rutherford
How did Thomson build upon Dalton's model?
He discovered subatomic particles (electron).
What contribution did John Dalton make to atomic theory?
He discovered that every element consisted of one type of atom that couldn't be divided.
What scientist is best known for his "Plum Pudding" model of the atom?
J.J. Thomson Model
He discovered the electron using cathode ray tube experiment.
Joseph Thomson
What subatomic particle is electrically neutral (no charge)?
Neutron
His atomic model was depicted similar to a planetary/solar system
Niels Bohr
A tiny but very dense, positively charged portion of the atom that holds most of the atomic mass
Nucleus
Which subatomic particles contribute the most to the mass of an atom?
Protons and Neutrons
He first measured the mass and charge of an electron using the oil drop experiment.
Robert Millikan
An element is made up of only one kind of _____.
atom
An atom is made up mostly of
empty space
Where is most of the MASS of an atom located?
inside the nucleus
The electron has a ___.
negative charge
Which electrical charge does a neutron have?
neutral
the central region of an atom where its neutrons and protons are is its
nucleus
Subatomic particles with a positive charge
protons
The positive particles of an atom are
protons
What does the nucleus of an atom contain?
protons and neutrons
Which two particles are in the atomic nucleus?
protons and neutrons
Rutherford's gold foil experiment provided evidence that...
there is a dense positively charged nucleus at the center of an atom.
Who's model is this?
Rutherford
all matter is made of what
atoms