Group 7 - chemical properties

• What is the vertical column of non-metal elements next to group 0 in the periodic table called?

  Group 7, also known as the halogens
• Why do elements in the same group of the periodic table show similar chemical properties?

  They have the same number of electrons in their outer shell
• What is the definition of a halogen?

  An element placed in group 7 of the periodic table
• What does the term 'chemical reaction' refer to?

  A change in which atoms are rearranged to form new substances
• What happens when a group 7 element takes part in a reaction?

  Its atoms each gain one electron
• What is formed when halogens react with metals?

  Salts
• What is the formula for sodium chloride?

  NaCl
• Write the balanced equation for the reaction of sodium with chlorine.

  $2Na(s) +$$Cl_2(g) \rightarrow 2NaCl(s)$
• What is the trend in reactivity of halogens as you move down group 7?

  The reactivity decreases down the group
• What are the reactions of halogens with iron wool?

  • Fluorine: Cold iron wool burns to produce white iron(III) fluoride
  • Chlorine: Hot iron wool burns vigorously to produce orange-brown iron(III) chloride
  • Bromine: Hot iron wool burns quickly to produce red-brown iron(III) bromide
  • Iodine: Hot iron wool reacts slowly in iodine vapour to produce grey iron(II) iodide
• What is the product when chlorine reacts with hydrogen?

  Hydrogen chloride
• What happens when hydrogen chloride dissolves in water?

  It produces hydrochloric acid
• What are the reactions of halogens with hydrogen?

  • Fluorine: Explodes at room temperature and in the dark, forming hydrogen fluoride
  • Chlorine: Explodes with a flame or in sunlight, forming hydrogen chloride
  • Bromine: Vigorous reaction when warmed with hydrogen, forming hydrogen bromide
  • Iodine: Very slow reaction when heated strongly, forming some hydrogen iodide
• What can be predicted about the reaction of astatine with hydrogen?

  Astatine should react very slowly with hydrogen, even when heated
• What is the expected product when astatine reacts with hydrogen?

  A small amount of hydrogen astatide should form
• What happens when hydrogen astatide dissolves in water?

  It forms an acidic solution