May 16 2011 - Bohr Diagram

ARE YOU READY FOR THIS?!?!  Well im not.  Which is why im doing this this blog in the first place.  Its time for the Bohr Model.  Yeah I know right?  This stuff is getting boring but we are almost done.  Just 8 more classes, just 8 more classes.

Niels Bohr proposed the Bohr Model in 1915.  It is a planetary model where negatively-charged electrons orbit the nucleus.  These electrons exist in orbitals and when energy is absorbed, they move to a higher orbital.  When energy is lost, electrons fall to a lower orbital.  

The Bohr diagrams places the number of neutrons and protons in the center and electrons in energy rings around the outside. Each energy ring has a maximum number it can hold

                     Ring 1 – 2 electrons

                     Ring 2 – 8 electrons

                     Ring 3 – 8 electrons

                     Ring 4 – 18 electrons

                     Ring 5 – 18 electrons

                     Ring 6 – 32 electrons

                     Ring 7 – 32 electrons

Drawing Bohr Diagrams

Lithium - two of its 3 electrons go into the first level.  the third electron goes into the second energy level.  

1. Draw a circle and write Li inside of the circle

2. Write the number of protons and neutrons in the circle , which is  3P and 4N

3. Draw an arc which represents the first energy level and label it 2e^-.  This will represent the 2 electrons 

    in this energy level.

4. Draw a second arc which represents the second energy level and label it 1e^- .  This represents the third electron.