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-
20 You should know how to draw a Bohr Diagram for the first 20 elements. Bohr DiagramsYou should know how to draw a Bohr Diagram for the first 20 elements.
21 Periodic Table Study Guide How to Draw Lewis StructuresBy Mrs. Hunt and Mrs. LaRosa2008
22 Lewis Structures Find the element on the periodic table. Determine the number of valence electrons.This is how many electrons you will draw.
23 Lewis Structures Find out which group (column) your element is in. This will tell you the number of valence electrons your element has.You will only draw the valence electrons.
24 Groups - Review Group 8 = 8 electrons Group 1 = 1 electron Except for He, it has 2 electronsGroup 1 = 1 electronGroup 2 = 2 electronsEach column is called a “group”3, 4, 5, 6, 7Each element in a group has the same number of electrons in their outer orbital, also known as “shells”.The electrons in the outer shell are called “valence electrons.”
25 C Lewis Structures Write the element symbol. Carbon is in the 4th group, so it has 4 valence electrons.Starting at the right, draw 4 electrons, or dots, counter-clockwise around the element symbol.C