Electron Configuration of Ions

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

  Work out electron configuration of ions
• What is an ion?

  An atom that has lost or gained electrons
• How many protons does a lithium atom contain?

  Three protons
• What charge do protons have?

  Positive charge
• How many electrons does a lithium atom contain?

  Three electrons
• What is the overall charge of a neutral lithium atom?

  No overall charge
• What happens to lithium atoms when they react?

  They lose the electron in the outer shell
• What is the charge of the lithium ion after losing an electron?

  One positive charge
• What is the lithium ion referred to as?

  The lithium ion
• What happens when atoms lose electrons?

  They form a positive ion
• How many protons and electrons does a beryllium atom have?

  Four protons and four electrons
• What charge does a beryllium ion have after losing electrons?

  Two positive charges
• How many protons and electrons does a fluorine atom have?

  Nine protons and nine electrons
• What happens to a fluorine atom when it gains an electron?

  It forms the fluoride ion
• What is the charge of the fluoride ion?

  One negative charge
• How many protons and electrons does an oxygen atom have?

  Eight protons and eight electrons
• What happens when an oxygen atom reacts?

  It gains two electrons
• What is the charge of the oxide ion?

  Two negative charges
• What is the key idea when atoms lose electrons?

  • Atoms form a positive ion
  • Example: Lithium loses one electron
  • Example: Beryllium loses two electrons
• What is the key idea when atoms gain electrons?

  • Atoms form a negative ion
  • Example: Fluorine gains one electron
  • Example: Oxygen gains two electrons
• What is the electron configuration of a magnesium atom?

  1s2 2s2 2p6 3s2
• What happens to the electron configuration when magnesium forms a magnesium ion?

  It loses two electrons from 3s subshell
• What is the electron configuration of the magnesium ion?

  1s2 2s2 2p6
• What is the electron configuration of a sulfur atom?

  1s2 2s2 2p6 3s2 3p4
• What is the electron configuration of the sulfur ion with a 2 negative charge?

  1s2 2s2 2p6 3s2 3p6
• What are the steps to write the electron configuration of ions?

  1. Identify the number of electrons
  2. Determine the charge of the ion
  3. Adjust the electron configuration based on electron loss or gain
• What is the focus of the last video in the series?

  Electron configuration of ions
• What forms an ion?

  When neutral atoms lose or gain electrons
• What happens when sodium loses its electrons?

  It forms a positive ion
• From which energy sub shell are electrons lost first in ions?

  From the highest energy sub shell
• How many electrons does aluminium lose to form its ion?

  Three electrons
• What is the charge of the aluminium ion?

  Three positive
• What is the electron configuration of the aluminium ion?

  1s2 2s2 2p6
• What is the order of filling for d-block elements' subshells?

  4s fills before 3d
• Why does the 4s subshell fill before the 3d subshell?

  Because it has lower energy initially
• What happens to the energy of the 4s subshell once it contains electrons?

  It becomes higher than the 3d subshell
• From which subshell are electrons lost first in d-block elements?

  From the 4s subshell
• What is the electron configuration of manganese?

  1s2 2s2 2p6 3s2 3p6 3d4
• How many electrons does manganese lose to form the ion Mn³⁺?

  Three electrons
• What is the electron configuration of the Mn³⁺ ion?

  1s2 2s2 2p6 3s2 3p6 3d4