electron energy levels

• What should you be able to do by the end of the video on electronic structure?

  Represent the electronic structure of elements and work out the group number of an element
• What does the atomic number of an element indicate?

  The atomic number indicates the number of protons in the nucleus
• How many protons are in the nucleus of a helium atom?

  Two protons
• How many electrons does a neutral helium atom have?

  Two electrons
• Where do electrons exist in an atom?

  Electrons exist in energy levels or electron shells
• What is the maximum number of electrons that the first energy level can hold?

  Two electrons
• What is the maximum number of electrons that the second energy level can hold?

  Eight electrons
• How many electrons can the third energy level hold?

  Eight electrons
• How do you assign electrons into energy levels for hydrogen?

  Place one electron in the first energy level
• How can you represent the number of electrons in hydrogen's energy level?

  By writing a one in brackets
• How many electrons does lithium have and how are they arranged?

  Lithium has three electrons: two in the first energy level and one in the second
• What does the number of electrons in the outer energy level indicate?

  It tells us the group number of that element in the periodic table
• In which group is lithium found in the periodic table?

  Group one
• How many electrons does boron have in its outer energy level?

  Three electrons
• In which group is boron found in the periodic table?

  Group three
• How many electrons does carbon have and how are they arranged?

  Carbon has six electrons: two in the first energy level and four in the outer energy level
• In which group is carbon found in the periodic table?

  Group four
• How many electrons does neon have in its outer energy level?

  Eight electrons
• What does a full outer energy level indicate about an element's group number?

  It indicates that the element is found in group zero
• What are the elements with a full outer energy level called?

  Noble gases
• How many electrons does sodium have in total?

  Eleven electrons
• How are the electrons arranged in sodium?

  Sodium has two electrons in the first energy level, eight in the second, and one in the third
• In which group is sodium found in the periodic table?

  Group one
• What is the process for determining the group number of an element in the periodic table based on its electron configuration?

  • Count the number of electrons in the outer energy level
  • The group number corresponds to this count
  • Example: Lithium has 1 electron in the outer level, so it is in group 1
• How do you represent the electron configuration for the first 20 elements in the periodic table?

  1. Identify the total number of electrons
  2. Fill the first energy level (max 2)
  3. Fill the second energy level (max 8)
  4. Fill the third energy level (max 8)
  5. Use brackets to indicate the number of electrons in each level