1 BUNSEN BURNER i Close the air hole and turn the gas tap full on Light the gas and hold a piece of wire in different parts of the flame moving it from the bottom to the top Note the hottest place in the flame Open the air hole Again hold the wire in the flame moving from the bottom to the top Note the hottest place in the flame Compare the two flames and note which has the hottest point ii Close the air hole Hold a testtube with its bottom end just above the flame Carbon deposits on the glass To test whether unburned carbon gives the yellow colour to the flame sprinkle powdered charcoal into the flame to see if this gives the same effect iii Open the air hole again Note whether carbon deposits on a testtube held in this flame Air mixing with the gas helps it to burn more rapidly and efficiently To test what is in the cooler inner cone hold a splint of wood in the flame so that it passes through the inner cone Note which part of the splint burns Hold a piece of glass tubing with one end in the inner cone then ignite the gas that comes out of the other end iv Investigate a candle flame and the flame of a spirit lamp in a similar way Find the hottest part of the flame Test for unburned carbon particles in the flame Look for an inner cone of unburned gases