Download Drawing Atomic Structure

Physical Science
Chapter 17: Atoms and the Periodic Table
Atomic Structure Notes
Review
What is an atom?
Atomic Symbol
- The shorthand abbreviation that is used to identify an ______________ (element name)
- Atomic symbols have
o A ______________ letter at the ______________ of the symbol (all symbols have this)
o Some have a _________________ case letter after the capital letter
 Be careful! The letters of the atomic symbol do not always match the name of
the element
o
o
Examples:
Hydrogen
Helium
Magnesium
Potassium
Iron
Sodium
__________
__________
__________
__________
__________
__________
Label the element name and atomic symbol on the diagram above
Nucleus (discovered by _________________ in 1911)
- The ______________ of the atom
-
Contains a majority of the _________ of the atom (99.9%), but a small portion of the _______
-
Relative size of the nucleus:
-
The nucleus contains:
o
Protons

Have a ______________ charge

Have a mass of ____________ grams or _____ atomic mass units (amu)

The number of _______________ determines the type of __________ that you
have!! (If you change the number of protons, you change the element!)

We call this the _____________________

Label the atomic number on the diagram above
Complete the table below. Use the Periodic Table on p. 518 to help you.
Element
Atomic Symbol
Atomic Number
# of Protons
29
Br
82
o
Neutrons (Discovered by _________________ in 1932)

Are __________________, which means they have no ______________

Have a mass of _______________ grams or _____ atomic mass units (amu)

To determine the number of neutrons in an atom, you need to know the atom’s
mass number

_________________: the ____________ of the number of
___________ and the number of __________ in the nucleus of an atom
o

# of Neutrons = _________________________________

If you are given the mass number and the number of neutrons, how
can you figure out the number of protons?
Protons and Neutrons can both be broken down even farther into _______________.
More info on pg. 508
Electrons (Discovered by ____________________ in 1904)
- Have a __________________ charge
-
Have a very small mass (approximately 9.1093 x 10-28 grams or _______________ amu)
-
In a ____________ atom, the total number of electrons ___________ the number of protons
-
Can be found in ____________________ surrounding the nucleus (Developed in 1926)
o
Electrons are so small and move so quickly that it is impossible to determine their
exact location however we can predict it based on probability
o
The electron cloud is approximately 100,000 times larger than the nucleus
o
Each electron cloud has a different amount of _______________
o
The electron clouds closest to the nucleus have the ___________ amount of energy,
and the electron clouds furthest from the nucleus have the _______________ energy
o
Electrons fill the energy levels from the __________ levels to the ____________ levels

Each level can hold a specific number of electrons
*Note: Remember the Bohr model (proposed in 1913 by _____________) is no longer the accepted
model for the atom, however it is easier to understand the behavior of electrons and where they are
located if we imagine the electron clouds as orbits.
Drawing Atomic Structure
Draw a diagram of a neutral atom for the element that contains 2 protons and has a mass number of 4.
Element name: _________________
Protons: ______
Electrons: ______
Neutrons: ______
p+= _____
n = _____
Draw a diagram of a neutral atom for the element that contains 12 protons and has a mass number of 24.
Element name: _________________
Protons: ______
Electrons: ______
Neutrons: ______
p+= _____
n = _____
Draw a diagram of a neutral atom for the element that contains 9 electrons and has a mass number of 19.
Element name: _________________
Protons: ______
Electrons: ______
Neutrons: ______
p+= _____
n = _____
Isotopes
 _______________ of the same ______________ that contain
the same number of protons, but a different number of
_______________

Because isotopes have a different number of neutrons, they also
have different ____________________.

Most elements have more than one isotope, and therefore have
an average ___________________.
o

The average atomic mass is the ______________________ mass of an element’s various
isotopes (takes into consideration which isotopes are more ______________ than others).
 The average atomic mass can be found on the Periodic Table. Label this on the
diagram on the first page.
Isotopes can be symbolized in a few ways:
1) Atomic symbol, mass number, and atomic number
14
6
C
2) Atomic name or symbol with a hyphen and ______________________.
Carbon-14 or
C-14