Interpreting Atomic Structure

Interpreting Atomic Diagrams # of shells an atom has depends upon # of electrons Each shell must have its full # of electrons before a new shell starts If there are more electrons than a shell can hold , a new shell starts Valence shell can hold only up to 8 electrons

Hydrogen # Protons= ______________ #neutrons=______________ #electrons=______________ Overall charge=___________ How many electron shells does a hydrogen atom have? e P

Helium e # Protons= ______________ #neutrons=______________ #electrons=______________ Overall charge=___________ How many electron shells does a helium atom have? Is the shell full? P N P N e

Beryllium # Protons= ______________ #neutrons=______________ #electrons=______________ Overall charge=___________ How many electron shells does beryllium have? Is the inner shell full? Is the outer shell full? e P N P N P N e e N N P e

Oxygen # Protons= ______________ #neutrons=______________ #electrons=______________ Overall charge=___________ How many electron shells does oxygen have? Is the inner shell full? Is the outer shell full? e e e P N P P N P N N e e N N N P N N P P P e e e

www.middleschoolscience.com 2008 How to Draw Bohr Diagrams www.middleschoolscience.com 2008

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 The families/groups tell us how many valence electrons an element has How many valence electrons does the following elements have? H He B O Ne

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

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

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. C

C 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. C

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

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

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

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

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

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

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