Chapter 17: Properties of Atoms
Date:_____________
Section 1: Structure of the Atom - Notes
Learning Goals:
 Identify the names and symbols of common elements.
 Identify quarks as subatomic particles of matter.
 Describe the electron cloud model of the atom.
 Explain how electrons are arranged in an atom.
Scientific Shorthand:
 Each element can be symbolized with a _____________________________________________.


o
A short or abbreviated way to write the name of an element.
o
Consist of one ____________________ letter plus one or two ________________ letters.
Some elements use the first letter or letters of their name to symbolize the element:
o
Aluminum __________
o
Carbon __________
o
Calcium __________
o
Nitrogen __________
The symbols of other elements are derived from Latin:
o
Sodium __________
o
Gold __________
o
Silver __________
o
Potassium __________
Atomic Components:
 An element is composed of _______________________________ of atom.
o
Atom: the ________________________ piece of matter that still _______________________
the properties of that element.

Atoms are composed of particles called
___________________, ____________________, and
______________________.

Protons and neutrons are found in a small, positively
charged center called the _______________________.

Protons are particles with an electrical charge of ______
o
They are made up of even smaller particles called
_________________.
o
Different elements have different _________________
of protons.

Neutrons are particles that ____________________ have an electrical charge.
o
They are also made up of even smaller particles called
________________________.
o

The number of neutrons in a single element may ___________
Electrons are particles with a charge of _______
o
___________________________ are 1/1836 the size of a ______________________ and can
be found somewhere in the electron cloud.
o
The ________________________________________________ in a single element may vary
Atomic Models:
 Atoms are incredibly _________________!
o
It would take ______________________________ stacked one on top of another to equal the
thickness of a sheet of aluminum foil.

We need ___________________________ in order to visualize and understand the atom.

400 B.C.
o _________________________________ proposed the idea that substances were made up of
tiny, indestructible particles called _______________.
o
_________________________________ claimed that matter was uniform throughout and
could be made of earth, water, air, or _______________.


1805:
o ____________________________________ offered proof that atoms exist
o

Aristotle’s theory was accepted for the next __________________ years!
Created an early model of the atom that showed a simple __________________
1926:
o The _________________________________ model was developed and is still used today
o
Electron cloud: the area around the nucleus of an atom where its electrons are_____________
________________________________________
o
The electron cloud is ________________________________ times
larger than the diameter of the nucleus.
o
Because electrons are so small and move so quickly, it is
______________________________ to describe their exact locations.