It is possible.
It is a source of power airsoft guns can run on. There are different power sources for most guns, such as spring, electric and gas. There are many different types of gas such as co2, propane, and green gas.
Definitely a gas pistol, You don't have to cock it between each shot
It all depends on the strength of the spring airsoft rifle. If your refering to pistols (I will assume you are), I prefer a co2 or green-gas pistol over a springer anyday. In the big picture, springers are regarded as cheap and useless. Although the fps may be better than that of the gas, it's range (and the fact that you need to cock spring guns after every shot,) it is usually better to save up your cash and buy a good gas pistol. However, even I need to admit that some springers (i.e. quality snipers {runs you about 90-110 American dollars}) are way better than their co2 and green-gas counterparts.
KWA 1911 sec MEU green gas pistol ------------------------------------------------ swith and Wesson sigma sw40f green gas pistol
It is a gas and can be used to propel projectiles.
No.
Electric pistols are not powerful. If you want power, I would recommend a green gas pistol.
Can't think of any great spring guns but for co2 there is the crossman c11 or I personally have a WE hicapa and love it but it uses green gas ( basically propane with some lub added).
Needs to be serviced
Varies by the pistol. Normaly better than spring.
No, Co2 airsoft guns run off disposable 12 gram cartridges, whereas green gas guns have internal storage and are refilled by propane tanks. Actually there are now dual use guns and adapters to use CO2 to fill green gas guns .
An air-soft gun that is powered by CO2 or green or red gas instead of a spring or a battery.