halogens and noble gases

• 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 halogens considered dangerous?

  They are all poisonous in various forms
• 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 compounds do halogens form with non-metals?

  Simple molecular structures
• What happens to melting and boiling points of halogens as you go down the group?

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

  Reactivity decreases as you go down the group
• 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
• 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 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
• How does the boiling point of noble gases change down the group?

  It increases as you go down the group
• What are the key 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 points increase down the group
  • Inert and non-flammable due to full outer shells
• What is the appearance of halide salts like KCl, KBr, and KI?

  They are colourless
• What color is bromine water?

  Orange
• What color is chlorine water?

  Colourless
• What color is iodine water?

  Brown
• What are the color changes in halogen displacement reactions?

  • Halide salts: Colourless
  • Bromine water: Orange
  • Chlorine water: Colourless
  • Iodine water: Brown
• what is a diatomic molecule

  when halogens exist as pairs of atoms
• what happens to the mp and bp of group 7 as you go down the group

  increase
• what happens to the reactivity of group 7 as you go down the group

  decreases
• why does the reactivity go down as you go down the group 7

  as you go down the outermost shell gets further and further away from the positive nucleus the attractive force gets weaker if it can't attract to get full outer shell it can't react
• how halogens form ionic bonds with metals

  when it gains an electron to form 1- ion we call it a halide
• halogens->halides

  fluorine->fluoride

  chlorine->chloride

  bromine->bromide

  iodine->iodide
• two of these properties are seen in group 7 elements?

  -They can form covalent bonds with other non-metals-Their ions usually have a 1- charge
• what is the most common to see halogens forming ionic compounds with-

  alkali metals in group 1 eg sodium chloride
• displacement reactions

  involve a more reactive halogen displacing a less reactive one
• what is rule of displacement reactions

  more reactive halogens will always displace less reactive ones
• what are group 0 known as

  noble gases
• what do noble gases all exist as

  colourless gases