1. ATOMIC STRUCTURE

2. Label the following:
Nucleus
protons
neutrons
electrons

3. Simplified view of the atom

4. Protons = positive charge + electrons= negative charge -
neutrons= no charge 0

5. ATOMIC MASS Inside the nucleus (mainly) protons + neutrons unit is AMU
find on periodic table (round to whole #)

8. ATOMIC NUMBER
Number of protons
cannot change!
Identifies element

10. IONS Charged atoms: NOT neutral p> e positive p< e negative
example: 11p 11e 12 n neutral Na
11p e n ion Na+

12. ISOTOPES Different number of neutrons than stable atom
usually radioactive
atomic mass is different than stable atom
example: U

15. History of atomic stucture
ttp://atomictimeline.net/index.php
Rutherford’s experiment

16. Can we see atoms? STM- scanning tunneling microscope Invented 1981
Shows arrangement of atoms
Gold

18. element- same atoms bonded together
Compound- two (or more) different atoms bonded
Mixtures- two (or more) different materials NOT bonded
Minerals?-

20. WORKSHEET P= e= n= atomic mass= atomic number=
how to recognize an ion?
How to recognize an isotope?

21. TO CALCULATE # OF NEUTRONS
Atomic mass (p+n)
atomic number (p)
SUBTRACT!

22. Sample problems 11 p 12 n 10 e 19 p 21n 19 e 25 p 30 n 21 e Cr+3
234 Pu