Electronic Strucutre

• 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 show?

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


  An atom
• What do electrons occupy in an atom?


  Electrons occupy energy levels, also called electron shells
• What is the central part of an atom called?


  The nucleus
• What is the plural of nucleus?


  Nuclei
• How do electrons fill the shells in an atom?

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


  2 electrons
• What is the maximum number of electrons in the second shell?


  8 electrons
• What is the maximum number of electrons in 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 does sodium have?


  11 protons
• How many electrons does sodium have?


  11 electrons
• How are the electrons distributed in sodium's electronic structure?


  Two electrons occupy the first shell, eight in the second, and one in the third
• How can sodium's electronic structure be written?


  As 2,8,1
• What does each shell represent in an electronic structure diagram?

  Each shell is shown as a circle
• How is each electron represented in an electronic structure diagram?

  Each electron is shown as a dot or a cross
• How is the electronic structure of an element linked to its position on the periodic table?

  The electronic structure determines the number of shells and electrons in the outermost shell
• What is the group number of sodium based on its electronic structure?

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

  Period 3
• What is the atomic number of sodium based on its electronic structure?

  11
• What does the total number of electrons in all shells equal for sodium?

  11 electrons
• 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
  • Total number of electrons in all shells equals the atomic number