SCH4U - Chemistry 12 (2024-25) - A

1-3D: Summary

• The Aufbau Principle states that electrons fill up orbitals with the lowest energy first
• Aufbau Diagrams can be used to determine the relative energy of the atomic orbitals
• Electron configurations display how the electrons in an atom are organized
• Orbital Diagrams also display how electrons are organized in an atom
• Hund's Rule states that electrons will fill up an empty orbital before pairing up with another electron in an orbital with the same energy
• The periodic table of the elements can be divided up into 4 blocks: s block, p block, d block & f block
• The last orbital to be filled with electrons in an element is what determines the block it is in
• Elements within a block have similar characteristics
• Elements with similar electron configurations have similar qualities
• Electron configuration can affect specific characteristics including electronegativity, melting point and boiling point