2. Elements Pure substance Only ONE type of atom Add together to make compounds Make up all chemical matter All known elements are in periodic table http://en.wikipedia.org/wiki/Chemical_element
4. Protons + 1 Positive Charge Found in Nucleus Atomic Number Defines Elements by Atomic Number http://en.wikipedia.org/wiki/Protons
5. Electrons - 1 Negative Charge Cancels out Proton Smallest particle in an atom Found in Cloud around Nucleus http://en.wikipedia.org/wiki/Electron http://chemistry.about.com/od/atomicmolecularstructure/a/aa062804a.htm
6. Electron Shells Only fixed number of electrons per Shell Shells fill from inside out 2 8 8 http://en.wikipedia.org/wiki/Electron_shell
7. Nobel Gases Last electron shell is full Not very reactive Flickr.comwww.destinysagent.com
8. Neutrons No Charge Balance atoms Found in Nucleus Cause Isotopes Svdmolen/Jeanot, Public Domain
10. Atomic Weight Measured in Atomic Mass Units (AMU) Protons and Neutrons Electrons are too small Weighted Average of All Isotopes http://education.jlab.org/qa/pen_number.html
11. Example A) What Atom and Atomic Symbol? B) How many protons? C) How many electrons in a neutral atom? D) How many Neutrons? Flickr.comwww.destinysagent.com
12. A) What atom/ atomic symbol? Titanium/ Ti B) How many Protons? 22 C) How many Electrons? 22
13. D) How many Neutrons? Atomic Weight ≈ 48 Amu Take Atomic Weight and subtract atomic number/ amount of protons The electrons are too small Number of Neutrons is 26
