1. Protons, Neutrons, and Electrons
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Complete
Protons, Neutrons, and Electrons
Practice Worksheet

2. YWBAT
List the three rules for writing the electron configuration of elements

3. Electron Configuration
Describes arrangement of electrons in an atom
Three rules
Aufbau Principle
Pauli Exclusion Principle
Hund’s rule

4. Electron Configuration
Aufbau Principle
An electron occupies the lowest energy orbital that can receive it.
Fill electrons lowest to highest energy
Hund’s Rule
- Orbitals of the same energy must be occupied by 1 electron before it can be occupied by two electrons
Pauli-Exclusion Principle
- Each orbital can only hold 2 electrons with opposite spins

5. The aufbau diagram shows the relative energy levels of the various atomic orbitals. Orbitals of greater energy are higher on the diagram.

6. Practice
Phosphorus has 15 electrons. Write the electron configuration for Phosphorus.

7. Practice
Phosphorus has 15 electrons. Write the electron configuration for Phosphorus. 1s22s22p63s23p3

10. Noble Gas Configuration
Find the element on the periodic table.
Go back to the last noble gas that was passed.
Write the symbol of the noble gas in brackets to start your electron configuration.
Continue your electron configuration using the row after the noble gas.

11. Noble Gas Configuration
Write the noble gas configuration for Osmium.
Osmium is element 76.
The last noble gas was Xenon.
Os: [Xe] 6s2 4f14 5d6

12. Quantum Number Review Principle Quantum Number (n)
Energy level
Row on periodic table
Angular Quantum Number (l)
Sublevels (s,p,d,f)
# sublevels = principle quantum number
# of orbitals = n2
Maximum number of electrons that can occupy an energy level is 2n2