Electron Configuration and Emission Spectrum 2015.notebook

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November 30, 2016

Oct 20­9:18 PM

Bohr and Electron Configurations

Aim: What does the electron configuration tell us about an atom?

-Ground state vs. excited state

Oct 24­5:37 PM

Principle Energy Levels

Q. How many PEL's does phosphorus have?

Q. How many electrons are located in each PEL?

The electron configuration tells us 2 things:1. How many principle energy levels the element has. 2. How many electrons are in each principle energy level (PEL).

3 occupied principle energy levels

2    ­    8    ­    5 1st PEL has 2e­n=1  n=2    n=3 2nd PEL has 8e­

3rd PEL has 5e­

Electron Configuration and Emission Spectrum 2015.notebook

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November 30, 2016

Oct 24­6:51 PM

Bohr's Theory1) Principle energy levels (shells) hold the electrons.

2) ‐Electrons closer to the nucleus have lower energy (more stable). ‐Electrons farther from the nucleus have higher energy (less stable).

Example: 2‐8‐6

3) Each energy level can only hold a maximum number of electrons based on the following formula:

• 2n2 where n= the # of principle energy level

4) A ground state atom has its electrons in the lowest energy levels possible and the configuration is found in the periodic table.

Nov 28­4:16 PM

Ground vs. Excited• The electron configuration in the periodic table is called the GROUND STATE configuration.

Electron Configuration and Emission Spectrum 2015.notebook

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November 30, 2016

Nov 28­4:16 PM

Ground vs. Excited• When electrons absorbed energy and they move up to higher energy levels, this is called an EXCITED STATE. It will be different from the ground state in the periodic table.

2­4 2­3­1

An electron jumped from the 2nd PEL to the 3rd PEL when the carbon atom absorbed energy and became excited.

Nov 28­4:55 PM

1. Given the following electron configurations, identify each element

2­8­8­1 _________________2­8­18­5 _________________2­1 _________________2­8­18­1 _________________2­8­2 _________________

2. Given the following electron configurations, determine whether the atom is in the ground state or excited state. Also identify each element.

2­8­16­2 _________ __________2­4­1 _________ __________2­8­7­1 _________ __________2­8­1 _________ __________2­7­6    _________ __________

Electron Configuration and Emission Spectrum 2015.notebook

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November 30, 2016

Nov 28­4:55 PM

3. Write the electron configuration for each of the following elements.

Boron _________________Chlorine _________________Potassium_________________Zinc_________________Iron_________________

4. Write the electron configuration for each of the following ions:

Li+1 _____________________Ca+2______________________

O­2 _____________________As+3______________________

Dec 16­5:25 PM

Electron Configuration and Emission Spectrum 2015.notebook

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November 30, 2016

Dec 16­5:28 PM