Group 7 & Group 0

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

  Group seven elements (halogens) and group zero elements (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?

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

  They don't really come up in the course
• What do we call pairs of atoms formed by halogens?

  Diatomic molecules
• How do halogens form diatomic molecules?


  By sharing electrons and forming a covalent bond
• What type of structures do compounds formed by halogens with non-metals have?


  Simple molecular structures
• What are the trends in 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?


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


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


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


  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?


  • Colorless gases
  • Full outer shells (inert)
  • Exist as single atoms
  • Non-flammable
• What happens to the boiling points of noble gases as you go down the group?


  Boiling points increase
• Why are noble gases considered inert?


  They have full outer shells and do not react with other atoms