Electronic structure

• Who made an early periodic table?

  Mendeleev
• How are elements arranged in the modern periodic table?

  Elements are arranged in order of atomic number in periods and groups
• What does electronic structure model represent?

  It models how electrons are arranged in atoms
• What is the smallest part of an element that can exist?

  An atom
• What is the nucleus of an atom composed of?

  The nucleus contains protons and neutrons
• What is the plural of nucleus?

  Nuclei
• How do electrons occupy energy levels in an atom?

  Electrons occupy the lowest available energy level first
• What is the maximum number of electrons that can occupy the first shell?

  2 electrons
• What is the maximum number of electrons that can occupy the second shell?

  8 electrons
• What is the maximum number of electrons that can occupy the third shell?

  8 electrons
• How can the electronic structure of an atom be predicted?

  It can be predicted from its atomic number
• What is the atomic number of sodium?

  11
• How many protons and electrons does a sodium atom have?

  Sodium has 11 protons and 11 electrons
• What is the electronic structure of sodium?

  2,8,1
• How is the electronic structure of an atom represented in a diagram?

  Each shell is shown as a circle and each electron as a dot or a cross
• What is the relationship between electronic structure and the periodic table?

  • The electronic structure is linked to the position on the periodic table
  • Number of shells corresponds to the period number
  • Number of electrons in the outermost shell corresponds to the group number
  • Atomic number is the sum of electrons in all shells
• What is the group number for sodium based on its electronic structure?

  1
• What is the period number for sodium based on its electronic structure?

  3
• How is the atomic number of sodium calculated from its electronic structure?

  It is calculated as the sum of electrons in all shells: \(2 + 8 + 1 = 11\)
• What are the features of electronic structure linked to the periodic table?

  • Number of shells corresponds to the period number
  • Number of electrons in the outermost shell corresponds to the group number
  • Atomic number is the sum of electrons in all shells