Surface to air is shot from the ground into the air at the target. Air to air is fired from another aircraft. Actually there is very little difference. just where the missile is fired from.
In Vietnam the US used Sparrows & Sidewinder air to air missiles. But ultimately the gun (20mm) proved to be a most commonly used weapon; by far by the NVAF MiG 17 & 19s.
Trishul is a surface to air missile . Trishul has a range of 9 km and is designed to counter a low level attack with a very quick reaction time. It is all all-weather surface-to-air-missile.
{|
|-
| They are typically referred to as SAMs. The Nike was the first one developed in the US. It was designed to shoot down ICBMs being fired at US targets.
|}
Exhaled air has high level of CO2 and water vapor while inhaled air has O2 and very little amount or no water vapor. There is nothing like expired air unless it stale long time trapped air and...