O2
It gives off carbon dioxide which proves that it respires.
Oxygen is given of
Oxygen
Gases are released through the stomata, on the underside of the leaf. There is more than one gas given off by the leaf, however. Carbon Dioxide is given off when the plant performs aerobic respiration; Oxygen and water vapor are given off during photosynthesis; and there are other gases that different plants give off at different times.
None, no gas is given off.
Ammonia gas (NH3) is given off when ammonia solution is heated.
hydrogen eg:Na+HCl------>NaCl+H2
Hydrogen gas is given off when magnesium reacts with sulfuric acid.
Carbon Dioxide is given off. (CO2)
Hydrogen gas.
Oxygen gas
Hydrogen gas is always given off when an acid solution is electrolyzed.