Atomic Theory Worksheet
Name: Valeria Garcia
Objective: You will create an abbreviated atomic theory timeline to show how the scientists involved in
the atomic theory worked together to construct the modern model of the atom.
Part 1 – Atomic Theory Timeline
Choose three scientists from the options below and complete the table.
Options: John Dalton, Niels Bohr, JJ Thomson, Erwin Schrödinger, Ernest Rutherford
Scientist 1
1803
John
Dalton
He belived
that all
matter is
made of
atoms,
atoms
cannot be
made or
destroyed,
all atoms
of a given
element
are
identical in
mass and
properties,
compound
s are
formed by
a
combinatio
n of two or
more
different
kinds of
atoms and
that a
chemical
reaction
occurs
when
atoms are
rearranged
.
Scientist 2
1911
Scientist 3
1913
Ernest Rutherford
Niels Bohr
Rutherford's model suggested an atom with a
very small positively charged center nucleus,
which contains most of the atom's mass. He
also proposed that atoms contain a cloud of
electrons that orbit around the nucleus and that
most of the atom is empty space.
Bohr's model had electrons that
orbit around the positively charged
nucleus in groups that have
different energy levels. The more
energy electrons contain, the
farther they will orbit from the
nucleus.
Part 2 – Reflection Questions
1. Describe two details of the modern atomic model. Atoms consist of a dense nucleus surrounded by a
cloud of electrons. Another detail is that the nucleus contains positively-charged protons and neutral
neutrons.
2. Explain how the atomic model has changed over time. The discovery of electrons showed that atoms
can be broken down into smaller parts. Niels Bohr improved Rutherford’s model by showing that
electrons occupy energy levels around the nucleus.
3. Why was scientific collaboration important for the development of the atomic theory?Collaboration
among scientists was important for the development of the atomic theory because it allowed for the
exchange of ideas and the sharing of knowledge. Scientists from different fields, worked together to
develop the theory and refine it over time.
4. Do you think the atomic model will change again? Why? Well if there is new information about that
subject then maybe it will. But, our techonolgy of now a days is very advanced so there maybe could be
a possibility but I highly doubt it.