Identifying elements using the flame test
Aim: To identify various metallic elements
using flame tests.
Apparatus: Various solutions of metallic
elements, stick, Bunsen burner
Method:
1. Light the Bunsen burner and put on a
hot (blue) flame. Leave it on until there is
very little ‘colour’ in the flame.
2. Dip the stick in each solution in turn
into the flame, waiting for it to become
clean between each spray.
3. Observe the colour changes in the
flame.
Results:
Draw up a table to record the results
Metallic element Colour in flame
RESULTS
Element
Lithium
Barium
Calcium
Potassium
Copper
Sodium
Flame colour
Crimson
Light green
Brick red
Lilac
Blue/green
Bright orange
Explanation of the flame test
When atoms are heated their electrons can jump
up to a higher energy level (orbit). The energy to
do this comes from the heat. The electrons
quickly jump back down to the lower energy
level. The energy gained to jump up is released
as electromagnetic energy. Some of it we see as
light.
Application – Fireworks and spectroscopy
instruments used to identify and quantify small
amounts of metals in forensic, pathology and
other analytical samples.