Group 7 and 0 (Halogens & Noble Gases)

• What are the two groups of elements discussed in the video?

  Group seven elements known as halogens and 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, also an antiseptic
• What is the state of iodine at room temperature?

  Iodine is a dark gray solid
• Why are astatine and tenocine mentioned in the video?

  They can be ignored because they don't really come up in the course
• What type of molecules do halogens form?

  Halogens exist as diatomic molecules
• How do halogens form diatomic molecules?

  By sharing electrons and forming a covalent bond
• What are simple molecular structures formed by halogens?

  Compounds like hydrogen fluoride or carbon tetrachloride
• What are the trends in the properties of halogens as you go down the group?

  • Melting points and boiling points increase
  • Reactivity decreases
• Why does reactivity decrease as you go down the group of halogens?

  Because the outermost shell gets further from the nucleus, weakening the attractive force
• What do we call a halogen that gains an electron?

  A halide
• What are the names of the halide ions formed from halogens?


  • Fluoride
  • Chloride
  • Bromide
  • Iodide
• With which group do halogens most often form ionic compounds?


  With alkali metals in group 1
• What is a displacement reaction involving halogens?

  A more reactive halogen displaces a less reactive one
• What happens when chlorine gas is pumped into a solution of potassium bromide?

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

  • Exist as colorless gases
  • Have full outer shells, making them inert
  • Exist as single atoms
  • Non-flammable
• What happens to the boiling point of noble gases as you go down the group?

  The boiling point increases
• What does it mean for noble gases to be inert?

  They do not react with other atoms