yes
Glider
A plane with no engine is a glider. They use the air currents to stay aloft.
A glider is an aircraft that does not have an engine. To fly it must be towed into the air by a vehicle or another aircraft.
Usually Gliders are pulled behind another plane with a cable. Once they are flying in the air the glider will release the cable and glide on it's own.
Plane, Helicopter, Glider, Parachute, Chopper, etc
Yes solvents are heavier than air
Nitrous Oxide is heavier than air.
Yes, argon is heavier than air. Argon has a higher density than air, so it will sink below the air in the atmosphere.
"Heavier than air" refers to airplanes.
An airplane is a heavier than air flying craft
Yes, LP gas is heavier than air.
Gas is heavier than oxygen. Cold air is heavir than hot air