Yes it does
The only general answer that's true in all cases is: Slower than in vacuum. The exact speed depends on which gas, and the density of the gas, which in turn depends on its temperature and pressure.
A mirror has no effect on the speed of light, but it has a radical effect on thevelocity of the wavefront, because it reverses the direction of the normalcomponent of the velocity.
It varies, depending on the gas, and on the properties of the gas (mainly temperature and pressure). But under "normal" circumstances, the speed of light in a gas is almost the same as the speed of light in a vacuum.
Exactly the same as its effect on the speed of light, since light and MW are the same identical physical phenomenon.
Gravity does not effect speed of light ,so velocity is constant. Even if it effect the effect is negligible. So in short answer is 3*108ms-1 -Thunder
I'm afraid nothing happens to the speed of light ever. Also "air" is consider'd a gas.
Speed is relative to the speed of light and gravity. So gravity could effect speed.
The speed will depend on the type of gas and on its density.
When light passes from air into a gas, its speed and direction may change depending on the properties of the gas. This change in speed and direction is known as refraction. Additionally, some of the light may be reflected back at the boundary between the air and gas, causing part of the light to bounce off.
Helium is a light bulbs filler gas. Due to different speed of sound, inhaling helium would made a duck like sound when speak. However, helium is not the laughing gas (though it give out funny effect). Laughing gas is actually nitrous oxide.
When temperature rises, the density of the medium changes. Speed of light through a medium is inversely proportional to the density of medium. So when the temperature increases, the density decreases and the speed of light in that medium increases. Note that this is the indirect effect of temperature. If light is travelling through vaccuum , then the temperature will have no effect on the speed of light.
Remains unaltered