1. Building Atoms

2. On a piece of paper…..

3. 2 new guys
Henry Mosely: Atomic number is the number of protons in an atom. The periodic table is organized by atomic number.
James Chadwick: Discovered neutrons. Neutrons are neutral in charge, equal in mass to a proton, and found in the center of the atom. He came up with Mass number: mass of a single atom.

4. Purpose of today
What does the periodic table tell us about the structure of different atom?

5. Post-Activity Questions
What information does the atomic number give you?
What information does the atomic number not give you?
How would you go about drawing an atom of Ne, neon? What information would you need and where would you find it?

6. More Post-Activity Questions
Which of the atomic particles contribute to the mass of an atom?
What did you discover when you compared the mass number to the atomic weight of the elements in the table?
Is it possible to predict the atomic weight of an element if you know the number of protons and neutrons?

7. Wrap-Up Use your periodic table to identify the following elements:
Atomic number 18
Has 3 electrons
Atomic mass of 16.0