True or false? atmospheric oxygen increased after the evolution of photosynthetic prokaryotes.

True

Explanation:

During the precambrian era the abundance of photosynthesizing prokaryotic organisms called as Cynobacteria increased. These organisms were capable of utilizing carbon dioxide present in the atmosphere and sunlight to produce oxygen as product. This process resulted in increase in abundance of oxygen into the earth atmosphere.

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.