Describe what you think an atom looks like. Monday 11/28 Day 1 Science Starters Sheet Agenda 1. Please have these Items on your desk. 2- Fill out your Agenda. Describe what you think an atom looks like. What are valance electrons?

Table of Contents Date Assignment Page 11/28(purple) Bohr Model Notes pg 56

Atomic Structure and Bohr Model How to Draw Bohr Diagrams www.middleschoolscience.com 2008

Created by G.Baker www.thesciencequeen.net What are elements? Elements are the alphabet to the language of molecules. To make molecules, you must have elements. Elements are made of atoms. While the atoms may have different weights and organization, they are all built in the same way. Information & picture from Chem4kids at http://www.chem4kids.com/files/atom_structure.html Created by G.Baker www.thesciencequeen.net

Created by G.Baker www.thesciencequeen.net Atom Models There are two models of the atoms we will be using in class, but there are many types of atom models. Bohr Model Lewis Dot Structure Created by G.Baker www.thesciencequeen.net

Bohr Diagrams Find your 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.

Bohr Diagrams Find out which period (row) your element is in. Elements in the 1st period have one energy level. Elements in the 2nd period have two energy levels, and so on. www.chem4kids.com

Bohr Diagrams Draw a nucleus with the protons and neutrons inside. Carbon is in the 2nd period, so it has two energy levels, or shells. Draw the shells around the nucleus.

Bohr Diagrams Add the electrons. Carbon has 6 electrons. The first shell can only hold 2 electrons.

Bohr Diagrams Since you have 2 electrons already drawn, you need to add 4 more. These go in the 2nd shell. Add one at a time -starting on the right side and going counter clock-wise.

Bohr Diagrams 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.

Bohr Diagrams Try the following elements on your own: H He O Al Ne K

Bohr Diagrams Try the following elements on your own: H – 1 electron Al Ne K

Bohr Diagrams Try the following elements on your own: H He - 2 electrons O Al Ne K

Bohr Diagrams Try the following elements on your own: H He O - 8 electrons Al Ne K

Bohr Diagrams Try the following elements on your own: H He O Al - 13 electrons Ne K

Bohr Diagrams Try the following elements on your own: H He O Al Ne - 10 electrons K

Bohr Diagrams Try the following elements on your own: H He O Al Ne K - 19 electrons

Bohr Diagrams End of Study Guide. You should know how to draw a Bohr Diagram for the first 20 elements.