Halogens and noble gases

• What are the group seven elements known as?

  Halogens
• 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 are diatomic molecules?

  Molecules consisting of two atoms
• What type of compounds do halogens form with non-metals?

  Simple molecular structures
• What is the trend in melting and boiling points of halogens as you go down the group?

  They increase as you go down
• Why does reactivity decrease in halogens down the group?

  Outermost shell is further from nucleus
• What are the names of halides formed from halogens?

  Fluoride, chloride, bromide, iodide
• What happens when chlorine gas is added to potassium bromide solution?

  Chlorine displaces bromine to form potassium chloride
• What are the characteristics of noble gases?

  Colorless gases, inert, non-flammable
• Why do noble gases exist as single atoms?

  They have full outer shells and are inert
• What is the trend in boiling points of noble gases as you go down the group?

  Boiling points increase as you go down