1. ©American Modeling Teachers Association 2014

2. Atoms
Protons and Neutrons hang around in the center area called the nucleus, while the electrons move around nucleus.
Here is a very simple diagram of a basic atom.
Click here to watch a video about Atom Basics
And here to watch a video about how small is an atom.
Note that electrons don’t really orbit the nucleus its just easier to draw them that way.

3. What is an Element?
An element is a pure substance and each element has its own unique atom.
Example a piece of gold is made of lots of gold atoms.

4. Fun song by, They Might Be Giants to introduce the elements
Click the image to open the video

5. Let’s look at this atom again. How many protons does it have?
Now look at you periodic table and see if you can find which element it is?
Click the Periodic Table image to open an interactive PT website

6. Can you find an element that is composed of atoms that have:
3 protons?
11 protons?
How many protons does one atom of gold have?

7. Atomic Number Tells the number of protons
So the atomic # tells you how many protons plus how many electrons it needs to balance out it the protons.
But to balance out the
+ charge how many electrons does it need to have?

8. Atomic Mass
The atomic mass tells you the mass of 1 atom.
All protons and neutrons have a mass of 1
The electron basically has a mass of 0.
So how many neutrons must an atom of Boron have?
(It is OK to round)
We already know an atom of Boron has 5 protons and 5 electrons, but how many neutrons does it have?
____ = 11
By the way the atomic mass is measured in atomic mass units (AU) Atoms are so tiny they get their own measurement unit – pretty cool?

9. Find Sodium on your Periodic Table
Tip: To figure out the neutrons, if it’s not already rounded on your P.T. -round the atomic mass before you subtract .
Figure out how many protons, neutrons and electrons are in 1 atom of sodium.

10. Find Neon on your Periodic Table
Figure out how many protons, neutrons and electrons are in 1 atom of sodium.