topic 6

• what name is used to describe group 0 of the periodic table

  noble gases
• how many electrons do noble gases have in their full outer she)


  0 they have no incomplete electron shells of electrons
• what does chemically inert mean

  not chemically active
• why are noble gases called chemically inert

  they have full outer electron shells . this is a very stable electron configuration , this means that the gases are very unreactive
• what properties of helium makes it suitable for use in balloons 


  it is less dense then air and it does not burn
• why is argon used to fill electric light bulbs

  it is very chemical inert meaning that it will stop the light bulb from burning away when it gets hot and reacts with oxygen , it is non flammable
• why is argon used for welding

  it provides an inert atmosphere which stops the hot metal from reacting with oxygen in the atmosphere
• give 2 properties of noble gases

  all of them are colourless gases at room temperature

  they are also all monatomic
• what is the trend in melting and boiling points in noble gases

  they increase as you go down group 1 , this is because as the atoms get bigger there are more intermolecular forces to break
• what is the trend in density in noble gases

  density increases as you go down the group
• why did noble gases take a long time to discover

  they are non flammable , unreactive and colourless gases
• how do you test for oxygen 


  place a glowing splint inside a test tube of gas , if the gas is oxygen , the splint will relight and burst into a flame