Group 1

• What are the elements in group 1 known as?


  Alkali metals
• How does reactivity change as you move down group 1 metals?

  • Reactivity increases as you go down the group
  • This is because outer electrons are further from the nucleus and more easily lost
• Why are Group 1 metals so reactive?

  • They all have 1 electron in their outer shell, which they lose easily to form +1 ions.
  • This makes them highly reactive, especially with water and oxygen.
• What are the physical properties of Group 1 metals?

  • Soft (can be cut with a knife)
  • Low density (Li, Na, K float on water)
  • Shiny when freshly cut, but quickly dull as they react with oxygen
  • Low melting and boiling points compared to other metals
• How do Group 1 metals react with oxygen?

  They form metal oxides
• How do Group 1 metals react with water?

  They react vigorously, producing a metal hydroxide and hydrogen gas.
• What are the observations when Group 1 metals react with water?

  • Fizzing (hydrogen gas released)
  • Metal floats and moves on surface
  • Metal disappears
  • Forms an alkaline solution (turns universal indicator purple)
  • Potassium may ignite with a lilac flame
• What happens to the pH of water when a Group 1 metal is added?

  The solution becomes alkaline (pH increases) due to the formation of a metal hydroxide.
• Why does reactivity increase down Group 1?

  • Outer electron is further from the nucleus
  • Less attraction between nucleus and outer electron
  • Electron is lost more easily, so reactivity increases