Electronic Structure C1

• What is the main topic discussed in the video?

  The arrangement of electrons in atoms
• Why do most atoms, like fluorine, have an incomplete outer shell of electrons?

  Because they need a full outer shell to be stable
• What happens if an atom does not have a full outer shell?

  It will react with another atom to gain or lose electrons
• What is the atomic number of sodium?


  11
• How many protons and electrons does sodium have?

  11 protons and 11 electrons
• How are electrons arranged around the nucleus of an atom?

  In shells or energy levels
• How many electrons can the first shell hold?

  2 electrons
• How many electrons can the second shell hold?

  8 electrons
• What is the best way to add electrons to the shells?

  Place a single electron in the top, right, bottom, and left positions before pairing
• Why is sodium considered unstable?

  It has only one electron in its outer shell
• What do most atoms want to do to achieve stability?

  React to form molecules or compounds
• What do noble gases have that makes them stable?

  A completely full outer shell
• What is the atomic number of argon?


  18
• How would you represent the electron structure of argon?

  2, 8, 8
• How do you draw electrons in diagrams?

  As crosses or dots
• What is the atomic number of calcium?

  20
• How would you represent the electron structure of calcium?

  2, 8, 8, 2
• Why is calcium considered unstable?

  It has only two electrons in its outer shell
• What happens to calcium when it loses two electrons?

  It becomes a calcium ion with a 2+ charge
• What is the electron structure of a calcium ion?

  2, 8, 8
• What is the atomic number of fluorine?

  9
• How many electrons does fluorine have in its outer shell?

  7 electrons
• What does fluorine need to become stable?

  It needs to gain one more electron
• What charge does a fluoride ion have?

  A charge of -1
• How would you represent the electron structure of a fluoride ion?

  2, 8
• What is the significance of having a full outer shell of electrons for an atom?

  • Atoms are stable with a full outer shell
  • Atoms with incomplete outer shells are reactive
  • Stability is achieved through gaining or losing electrons
• What is the process for determining the electron arrangement of an element?

  1. Find the atomic number
  2. Determine the number of electrons
  3. Fill the first shell with 2 electrons
  4. Fill the second shell with 8 electrons
  5. Fill the third shell with 8 electrons (if applicable)
  6. Write the electron structure in the format of numbers
• What are the differences between atoms and ions?

  • Atoms are neutral with equal protons and electrons
  • Ions have an overall charge due to loss or gain of electrons
  • Ions are represented with square brackets and charge notation