Unit 3: Electrons

An atom has electrons in the 1s orbital which is closest to the nucleus. The same atom also has electrons in the 2s orbital. Which electrons are higher energy?

• 1s

• 2s

What atom matches this electron configuration?
1s²2s²2p⁶3s²3p⁶4s²3d¹⁰

• Zinc
• Copper
• Nickel
• Germanium

What electron configuration matches an oxygen atom?

• 1s²2s²2p⁶3s2, 3p⁶4s²3d¹⁰4p⁵
• 1s²2s²2p⁴
• 1s²2s²2p⁶
• 1s²2s²2p⁶3s²3p⁶4s²3d¹

The electron configuration of an atom is 1s²2s²2p⁶.  The number of electrons in the atom is 

• 3
• 6
• 8
• 10

Which electron configuration belongs to Chlorine (Cl)?

• 1s² 2s² 2p⁶ 3s² 3p⁵
• 1s² 2s² 2p⁶ 3s² 3p⁶
• 1s² 2s² 2p⁶ 3s² 3p⁷

Identify the Electron Configuration for Aluminum (Al)

• 1s² 2s² 2p⁶ 3s² 3p¹
• 1s² 2s² 2p⁶ 3s² 3p³
• 1s² 2s² 2p⁶ 3s² 4p¹

Electrons occupy orbitals of lowest energy first is part of what electron configuration rule?

• Hund’s Rule
• Aufbau Principle
  
• Pauli Exclusion Principle

What does Pauli exclusion principle state ?

• states that each electron occupies the lowest energy orbital available

• states that -no two electrons in the same orbital can have the same spin

• states that single electrons electrons with the same spin must occupy each-energy orbital before additional electrons with opposite spins can occupy the same orbitals

What atom matches this electron configuration?
1s² 2s² 2p⁶ 3s²

• Neon
• Magnesium
• Aluminum
• Potassium

What is the maximum number of electrons that an s subshell can have?

• 1 electron

• 2 electrons

• 3 electrons

• 4 electrons