electrons and shells

• Where are electrons found in an atom?

  In electron shells around the nucleus
• How are electrons represented in particle diagrams?

  As dots or small circles around the nucleus
• What is the relative mass of an electron?

  Approximately 1/1836 of a proton
• What is the charge on an electron?

  Negative charge
• How are elements arranged in the periodic table?

  By increasing atomic number
• Define an isotope.

  Atoms with the same protons but different neutrons
• How many protons, neutrons, and electrons are found in an atom of fluorine (F)?

  9 protons, 10 neutrons, 9 electrons
• What is the learning objective regarding electron arrangements?

  • Recall particle arrangement in atoms
  • Draw diagrams for helium
  • Represent electrons for different atoms
  • Fill in table for first 20 elements
  • Express electron arrangements as numbers
  • Draw electron shell diagrams for first 20 elements
• How many electrons are in a lithium (Li) atom?

  3 electrons
• What is the diagram representation of a lithium atom?

  Electrons arranged in shells around nucleus
• How many shells do lithium, beryllium, and boron have?

  All have 2 shells
• Which row of the periodic table are lithium, beryllium, and boron in?

  Row 2
• How many electrons are in the outer shell of lithium, beryllium, and boron?

  1, 2, and 3 electrons respectively
• Which group are lithium, beryllium, and boron in?

  Group 1 and Group 2
• Draw the electron arrangements for sodium and potassium.

  Both have 3 and 4 shells respectively
• How many shells do sodium and potassium have?

  Sodium has 3, potassium has 4
• Which row of the periodic table are sodium and potassium in?

  Row 3 and Row 4
• How many electrons are in the outer shell of sodium and potassium?

  Both have 1 electron in outer shell
• Which group are sodium and potassium in?

  Group 1
• What are the electron configurations of the first 20 elements?

  • Hydrogen: 1
  • Helium: 2
  • Lithium: 2, 1
  • Beryllium: 2, 2
  • Boron: 2, 3
  • Carbon: 2, 4
  • Nitrogen: 2, 5
  • Oxygen: 2, 6
  • Fluorine: 2, 7
  • Neon: 2, 8
  • Sodium: 2, 8, 1
  • Magnesium: 2, 8, 2
  • Aluminum: 2, 8, 3
  • Silicon: 2, 8, 4
  • Phosphorus: 2, 8, 5
  • Sulfur: 2, 8, 6
  • Chlorine: 2, 8, 7
  • Argon: 2, 8, 8
  • Potassium: 2, 8, 8, 1
  • Calcium: 2, 8, 8, 2