Electron

• What does the atomic number indicate?

  Number of protons in the nucleus
• How many protons are in a helium atom?

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

  Two electrons
• What are energy levels in an atom also called?

  Electron shells
• What is the maximum number of electrons the first energy level can hold?

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

  Eight electrons
• What is the maximum number of electrons the third energy level can hold?

  Eight electrons
• How do we assign electrons into energy levels?

  Based on the number of electrons in the atom
• How many electrons does a hydrogen atom have?

  One electron
• How can we represent the electron configuration of hydrogen?

  By writing a one in brackets
• How many electrons does a helium atom have?

  Two electrons
• How do we represent the electron configuration of helium?

  By writing a two in brackets
• How many electrons does a lithium atom have?

  Three electrons
• How do we represent the electron configuration of lithium?

  By writing a two followed by a one in brackets
• What does the number of electrons in the outer energy level indicate?

  It tells us the group number of the element
• In which group is lithium found?

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

  Three electrons
• In which group is boron found?

  Group three
• How many electrons does carbon have in total?

  Six electrons
• How do we represent the electron configuration of carbon?

  Two in the first level, four in the outer level
• In which group is carbon found?

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

  Eight electrons
• What group is neon found in?

  Group zero
• What are elements with a full outer energy level called?

  Noble gases
• How many electrons does sodium have?

  Eleven electrons
• How do we represent the electron configuration of sodium?

  Two in the first, eight in the second, one in the third
• In which group is sodium found?

  Group one
• What is the process for determining the group number of an element?

  • Count the number of electrons in the outer energy level
  • The group number corresponds to this count
• How do you draw electron energy levels for the first 20 elements?

  1. Identify the 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)