group 1

• What are the elements in Group 1 of the periodic table called?

  Alkali metals
• How many electrons are in the outer shell of alkali metals?

  One electron
• What happens to the outer electron of alkali metals during chemical reactions?

  It is usually given away
• Which alkali metal is the least reactive?

  Lithium
• What color flame does lithium produce when it reacts with oxygen?

  Crimson flame
• What occurs when lithium is placed in water?

  It floats and releases hydrogen gas
• Why is sodium more reactive than lithium?

  Its outer electron is less strongly attracted
• What happens to sodium when it is placed in water?

  It floats and melts due to heat
• What color flame does sodium produce when it reacts with oxygen?

  Yellow/orange flame
• What are the general properties of alkali metals?

  • Group 1 elements
  • One electron in outer shell
  • Highly reactive
  • Form positive ions
• Describe the reactivity trend among alkali metals.

  • Reactivity increases down the group
  • Lithium is least reactive
  • Sodium is more reactive than lithium
  • Potassium is more reactive than sodium
• What are the typical reactions of alkali metals with water?

  • Float on water
  • Produce hydrogen gas
  • Release heat
  • Form hydroxides
• Which element is more reactive, potassium or sodium?


  Potassium
• Why is potassium more reactive than lithium and sodium?

  Its outer electron is least attracted to the nucleus
• What happens when potassium is placed in water?

  It floats and reacts vigorously
• What color flame does potassium produce when it burns in oxygen?

  Lilac
• How does the reaction of potassium with water compare to sodium?

  Potassium's reaction is more vigorous
• What are the key properties of potassium in reactions?

  • More reactive than lithium and sodium
  • Floats on water and reacts vigorously
  • Burns with a lilac flame in oxygen
• examples of group 1 / alkali metals

  • Lithium (Li)
  • Sodium (Na)
  • Potassium (K)
  • Rubidium (Rb)
  • Caesium (Cs)
  • Francium (Fr)
• physical properties of alkali metals


  • soft, low density, low melting point, more reactive than other metals
• what happens when you go down group 1

  elements become even more reactive
• what happens to the melting and boiling points as you go down group 1

  they decrease
• why the reactivity of group 1 metals increases as you go down the group.

  The atomic radius increases down the group (larger atom) .The force of attraction between the nucleus and outer electron decreases. The electron is lost more easily (requires less energy to remove) from atoms lower down the group.
• Alkali metals react with water. Which two products are formed?

  Alkali metal + water ➔ metal hydroxide + hydrogen
• compounds formed when alkali metals react with oxygen

  1. Lithium reacts with oxygen to form lithium oxide, Li2O.
  2. Sodium reacts with oxygen to form sodium oxide, Na2O or sodium peroxide, Na2O2. 
  3. Potassium reacts with oxygen to form potassium peroxide, K2O2, or potassium superoxide, KO2.
•  two properties of the Group 1 metals:

  -Reactive-soft
• When sodium reacts with chlorine it forms an ionic salt called  .

  sodium chloride
• the normal colour of sodium chloride

  white