Moment and metals

• Moment


  The turning effect of a force around a fixed point called a pivot
• Calculating moment of a force


  Force (N) x Perpendicular distance (m)
• The principle of moments: when an object is in equilibrium, the sum of the clockwise moments is equal to the sum of the anticlockwise moments
• Group 1 Metals (Alkali Metals)


  • Lithium (Li)
  • Sodium (Na)
  • Potassium (K)
  • Rubidium (Rb)
  • Cesium (Cs)
  • Francium (Fr)
• Alkali Metals


  • Good conductors of electricity and heat
  • Shiny when freshly cut
  • Cause universal indicator to turn blue/purple
• Group 7 Halogens


  • Fluorine (F)
  • Chlorine (Cl)
  • Bromine (Br)
  • Iodine (I)
  • Astatine (At)
• Halogens


  • Have low melting points
  • Don't conduct electricity
  • As you go down the group, melting and boiling points increase
  • Elements change state at room temperature from gas to solid
• Noble Gases


  • Have low melting points
  • Colourless gases at room temperature
  • Inert (unreactive)
  • Take part in very few reactions