What causes a Flame?

If there is not a sufficient supply of oxygen, the flame will be smoky from excess of carbon.

A luminous flame causes the beaker to have soot at the bottom and the luminous flame also does not heat it up properly.

Flame luminosity occurs because of lack of oxygen. Also, the air holes in the Bunsen burner affects the flame.

insufficient secondary air

the flame will be smokey from the excess of carbon, when the oxygen is not sufficient

The flame changes colour due to the air getting to it, E.G. A bunson burner can change the colour of the flame bye opening and closing a switch which controls the amount of air getting to the flame.

Your air ports are closed down too far.

because it's hot

a different color flame, will indicate the different levels of oxygen intake of the flame. when the flame is blue, it indicates that the flame has a very low amount of O2 in the gas which is trying to burn. And when the flame is RED, means that there is more oxygen available when it is burnt.

The sodium turns the flame bright orange..

The luminescence in the cooler yellow flame is caused by closing the air vents of a Bunsen burner. This is the result of incomplete combustion.

Blue is in a flame because of light and temperature. Blue flames are hotter than other flame colors due to a more complete combustion that helps the gas molecules ionize. This causes them to appear blue.

Lack of oxygen, or some table salt (solution)

The wax should be over or there must be shortage of oxygen

Closing the gas tap a little reduces the amount of gas flowing into the burner. This causes a reduction in flame.