Chemistry
Chapter 4 The Atom
Name _____________________________________
10-14-13
I CAN _______________________________________________________________________________________
____________________________________________________________________________________________


An atom is the _________________________________ that______________________________________.
Atoms have ________________________:


A __________________________
An _________________________
THE NUCLEUS

The NUCLEUS of the atom is the ________________, ______________, ________________ central region
of the atom.

The NUCLEUS is made up of ___________ smaller particles [ ______________________________ ] called:
______________________ and ___________________
PROTONS

PROTONS are sub-atomic particles that have a _______________________________________________.

Represented by the symbol

The most important thing about protons is that they ____________________________________________.
_________
THE ATOMIC NUMBER

The number of P___________________ in an atom’s nucleus is called the ________________________ of
the atom.

Atoms can have from _____________________________, depending on which element is being referenced.

________________________________ determines which element an atom belongs to.
NEUTRONS

NEUTRONS are the other subatomic particle found in the atom’s nucleus.

NEUTRONS are _______________________; they have _______________________________________.

The symbol for a NEUTRON is: _____________
THE ATOMIC MASS NUMBER

The ____________________________ is the _______________________________________________ in
the atom’s nucleus.

Together, the protons and neutrons are responsible for 99.999% of the atom’s total mass.
PRACTICE PROBLEMS
An atom has 12 protons and 14 neutrons.
a. What is the atomic number of the atom? ____________
b. A atoms contains 33 protons and 41 neutrons.
The atomic mass number ? ____________
AN = ________
AMN = ________

While ALL atoms of an element have the ______________________________________ they don’t all have
the same number of _____________________.


The number of NEUTRONS can vary between atoms of the same element.
While ALL atoms of an element have the SAME NUMBER of PROTONS they don’t all have the same number
of NEUTRONS….

The number of NEUTRONS can vary between atoms of the same element.

Look at a Periodic Table. The Atomic Mass Number is found at the BOTTOM of each element’s square.

Now look at the ATOMIC MASS NUMBERS for the elements.

What do you notice about these numbers?
_________________________________________________________________
HOW DO ATOMIC NUMBERS GET THEIR DECIMALS?

We learned earlier that the AMN is the total of an atoms __________________________________________.

How can this give a number with a decimal?

While ALL atoms of an element have the ________________________________________ they don’t all
have the same number of _____________________….

The number of _________________________ can vary between atoms of the same element.
ISOTOPES

Atoms of an element that have differing numbers of NEUTRONS are called ________________________.

The ATOMIC MASS NUMBER reported for an element on the PERIODIC TABLE is _________________
______________________________________________________ of that element.
WRITING ISOTOPES

Isotopes can be written two ways:

1. Write the ___________________________ and _________________ (simple)
Example
2. Write the ____________________, ____________ and ___________ (more detailed)
Example