Water and carbon dioxide are given off.
Carbon dioxide
Carbon dioxide is a greenhouse gas given off during decomposition. When organic matter breaks down, it releases carbon dioxide into the atmosphere as a byproduct of microbial respiration.
during photosynthesis plants take in carbon dioxide and give out oxygen
During cellular respiration, two things given off are carbon dioxide and water. These byproducts are released as a result of the breakdown of glucose and other molecules to produce energy.
When they breathe out. Also after they die, during decomposition.
During decomposition, carbon dioxide (CO2) is the primary greenhouse gas emitted. As organic matter breaks down, microorganisms consume it and release CO2 as a byproduct of respiration. Additionally, methane (CH4) may also be produced in anaerobic conditions, particularly in waterlogged environments where decomposition occurs without oxygen. These gases contribute to the greenhouse effect, trapping heat in the atmosphere.
carbon dioxide is produced when it is heated
Carbon dioxide (CO2) is released during the decomposition process as organic matter breaks down and is broken down by bacteria and fungi.
The gas is Carbon dioxide, formed by the decomposition of Calcium carbonate it the Marble or Limestone
Oxygen
Plants give off oxygen during photosynthesis and carbon dioxide during respiration.
This is because, all thermal decomposition ( and all decomposition processes ) is an exothermic process. Well, if you need a full explanation, here goes. More energy is given off to form bonds then taken in to break bonds hence it is an exothermic reaction. Also, decomposition gives off heat energy.