M4 The
Periodic Table: Group 1 & 2 metals
Slide 21 of 42
Reaction with water
The reaction is more and more violent down the
group.
While lithium reacts quietly with water, sodium
darts about making a fizzing sound and at the end may produce a
pop sound when the hydrogen catches on fire.
Potassium when introduced into the water produces
a burning flame (see picture).
The gas produced can be identified as hydrogen
by testing it with a lit splint.
–When a
lit splint is applied to the mouth of a test tube containing
hydrogen, it burns with a characteristic ‘pop’ sound.
