1.12 Group 7 & Group 0 (Halogens & Noble Gases)

• 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 halogen atoms?

  Diatomic molecules
• How do halogens form diatomic molecules?

  By sharing electrons and forming a covalent bond
• What type of structures do halogen compounds form with non-metals?

  Simple molecular structures
• 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 as you go down the group?

  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 the halides formed from halogens?

  Fluoride, chloride, bromide, iodide
• With which group 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, inert, non-flammable
• Why do noble gases exist as single atoms?

  Because they have full outer shells and do not react
• How does the boiling point of noble gases change as you go down the group?

  It increases
• What are the main trends in the properties of halogens and noble gases?

  Halogens:

  • Melting and boiling points increase down the group
  • Reactivity decreases down the group

  
  

  Noble Gases:

  • Boiling point increases down the group
  • Inert and non-flammable