Question

small piece of sodium is dropped into a breaker of water give two reasons why this reaction involved a chemical change

Answer 1

1) Elemental sodium is placed in water.
2) The sodium reacts with water and begins to melt.

Answer 2

(i) When Na metal is dropped inwater.it reacts violently to form sodium hydroxide and hydrogen gas.The chemical equation involved in the reaction is:
2Na,,,+2H2O->2NaOH+H2O,g
(ii)On being heated in air,sodium reacts vigorously with oxygen to form sodium peroxide.The chemical equation involved in the reaction is:
2Na+O2->Na2O2