Oh, dude, closing the air holes restricts the airflow to the flame, which reduces the amount of oxygen available for combustion. This makes the flame less intense and decreases the chances of it getting out of control. So, yeah, it's safer because you're basically suffocating the flame a bit. Like, it's like putting a lid on a pot to simmer down the heat.
When air holes are closed, oxygen supply decreases, leading to incomplete combustion and the production of soot particles. These soot particles can get heated up to incandescence and emit visible light, creating a luminous flame. The presence of carbon in the soot is what causes the flame to appear luminous.
A bunsen burner (as used in a science lab or science classroom) will burn quietly, and a flickery yellow (like a wax candle) if the air hole is closed, or closed too much. If the air holes is opened, the flame will turn bluish and become noisy and hotter as more air mixes with the gas.
When the air holes of a Bunsen burner are closed, the flame will turn yellow and become sooty due to incomplete combustion. This is because the lack of oxygen restricts the amount of air reaching the flame, leading to inefficient burning of the fuel gas.
The outer cone of a Bunsen burner is the blue, luminous flame that surrounds the inner blue cone. It is where complete combustion of the gas occurs due to the influx of oxygen from the air holes at the base of the Bunsen burner. Adjusting the airflow controls the size and intensity of the outer cone.
If the air holes are open too much, it can lead to an influx of oxygen that may cause the flame to burn too hot and inefficiently. This can result in increased fuel consumption, uneven heating, and even potential safety hazards. Adjusting the air holes to the correct setting helps maintain a steady and controlled flame.
When air holes are closed, oxygen supply decreases, leading to incomplete combustion and the production of soot particles. These soot particles can get heated up to incandescence and emit visible light, creating a luminous flame. The presence of carbon in the soot is what causes the flame to appear luminous.
A luminous gas flame appears yellow or orange due to incomplete combustion, which produces soot particles that emit light when heated. The mixture of fuel and air in the flame is not perfectly balanced, leading to an excess of fuel that results in the incomplete combustion process.
A bunsen burner (as used in a science lab or science classroom) will burn quietly, and a flickery yellow (like a wax candle) if the air hole is closed, or closed too much. If the air holes is opened, the flame will turn bluish and become noisy and hotter as more air mixes with the gas.
When the air holes of a Bunsen burner are closed, the flame will turn yellow and become sooty due to incomplete combustion. This is because the lack of oxygen restricts the amount of air reaching the flame, leading to inefficient burning of the fuel gas.
luminous flame is the flame when you have not opened the air hole of your Bunsen burner. it moves around a lot. it looks a bit like the flame you find on candles. only it's a lot bigger. non-luminous flame is the flame when you have opened the air holes of your Bunsen burner. it's really steady, coloured blue only with no orange around it. sometimes though, you'll see small orange flames going up and disappears. ---------------------------------------------- Luminous: emitting light A luminous flame is created from an exothermic reaction (normally oxidisation) between that also emits visible light (EM radiation of wavelength 390[violet light]-750nm[red light]). A non-luminous flame is one that doesn't (EM radiation of wavelength<390nm but >750nm) Basically, if a reaction is making lots of heat (your normal, yellow Bunsen burner flame is at about 700^C) and you can see it, it's luminous. If you can't see it (and the heat is there) then it's non-luminous) [The yellow Bunsen burner flame is from the oxidisation of carbon molecules left over from the methane-oxygen reaction. The blue one is too, it's just happening faster so the wavelength decreases - ask your local physics teacher or put 100nm into Wikipedia search]
Safety flame
The flame will start to weaken and eventually go out as you cover the air holes. This is because the flame needs oxygen to sustain combustion, and by covering the air holes, you are restricting the flow of air needed for the flame to burn.
You would turn the collar on a Bunsen Burner so that the holes are exposing the flame to more oxygen to produce a blue flame. Close the holes by turning the collar to turn it back to the yellow (dirty) flame.
The most efficient flame that a Bunsen burner can produce should be pale light blue, and almost invisible. A yellow or luminous flame should be avoided as it isn't as hot as the blue flame and leaves sut.
Planets like Earth are not luminous and instead reflect light from the sun to appear visible in the night sky. These objects do not emit their own light like stars do.
Flame luminosity occurs because of lack of oxygen. Also, the air holes in the Bunsen burner affects the flame.
Opening the air holes increases the amount of air mixing with the gas, resulting in a hotter and more efficient flame. Closing the air holes reduces the amount of air mixing with the gas, leading to a cooler and less efficient flame. Adjusting the air holes allows for better control of the flame temperature.