Presentation on theme: "Bohr Models are NOT Boring!"— Presentation transcript:
1 Bohr Models are NOT Boring! How to Draw Bohr Diagrams
2 Bohr Diagrams Find the element on the periodic table. Determine the number of electrons--it is the same as the atomic number.This is how many electrons you will draw.
3 Bohr Diagrams Find out which period (row) your element is in. 1234567Elements in the 1st period have one energy level.Elements in the 2nd period have two energy levels, and so on.
4 Bohr Diagrams C Draw a nucleus with the element symbol inside. Write the number of Protons and Neutrons the element has inside the nucleus. Put a + by the P and a little 0 by the N.CP+ = 6N0 = 6Note: Round mass to nearest 1 when figuring neutrons.
5 The electron shells surrounding the nucleus each hold a particular number of electrons. Shells are named with letters:1 = K shell = 2 electrons2 = L shell = 8 electrons3 = M shell = 8 electrons4 = N shell = 18 electrons5-7 = O, P, Q = up to 32 electronsRemember: The outer shell of an atom (no matter what letter) can only hold 8 electrons!
6 Bohr DiagramsCarbon is in the 2nd period, so it has two energy levels, or shells.Draw the shells around the nucleus.CP+ = 6N0 = 6
7 Bohr Diagrams C Add the electrons. Carbon has 6 electrons. The first shell can only hold 2 electrons.Write the number of electrons that shell holds and e- for electrons an their charge.How many electrons are in the outer shell?CP+ = 6N0 = 62 e-
8 Bohr DiagramsSince you have 2 electrons in the first shell, you need to add 4 more.CP+ = 6N0 = 6These go in the 2nd shell.Again, write e- and the number of electrons.2e-4e-
9 Bohr Diagrams C Check your work. You should have 6 total electrons for Carbon.Only two electrons can fit in the 1st shell.The 2nd shell can hold up to 8 electrons.The 3rd shell can hold 18, but the elements in the first few periods only use 8 electrons. We’ll talk about how they fill tomorrow.CP+ = 6N0 = 62e-4e-