halogens and noble gases year 9

• What is a covalent bond?

  A bond where atoms share electrons
• How do covalent bonds achieve stability for atoms?

  By allowing atoms to attain noble gas configuration
• Between which types of atoms do covalent bonds typically form?

  Nonmetal atoms
• What determines the strength of a covalent bond?

  The number of shared electron pairs
• How many pairs of electrons are involved in a single covalent bond?

  One pair of shared electrons
• How many pairs of electrons are involved in a double covalent bond?

  Two pairs of shared electrons
• What is the role of covalent bonds in chemistry?

  • Essential for forming molecules
  • Crucial for structure and function of substances
• Why are covalent bonds important in the context of chemistry?

  They form molecules and determine substance properties
• What are the group seven elements known as?

  Halogens
• What are the group zero elements known as?

  Noble gases
• What are the properties of halogens?

  • Fluorine: poisonous yellow gas, very reactive
  • Chlorine: poisonous green gas, less reactive
  • Bromine: reddish-brown volatile liquid, poisonous
  • Iodine: dark gray solid, forms poisonous purple vapors, antiseptic
• What is the state of fluorine at room temperature?

  Poisonous yellow gas
• What is the state of chlorine at room temperature?

  Poisonous green gas
• What is the state of bromine at room temperature?

  Reddish-brown volatile liquid
• What is the state of iodine at room temperature?

  Dark gray solid
• Why are astatine and tenocine often ignored in the course?


  They don't really come up in the course
• What are diatomic molecules?

  Molecules consisting of two atoms
• How do halogens form diatomic molecules?

  By sharing electrons and forming covalent bonds
• What type of structures do halogens form with other non-metals?

  Simple molecular structures
• What is an example of a compound formed by halogens?

  Hydrogen fluoride
• What happens to the melting and boiling points of halogens as you go down the group?

  They increase
• How does reactivity change among halogens as you go down the group?

  Reactivity decreases
• Why does reactivity decrease in halogens down the group?

  Outermost shell gets further from nucleus
• What do we call a halogen that gains an electron?

  Halide
• What are the names of halides formed from halogens?

  Fluoride, chloride, bromide, iodide