What are the 3 photosynthesizing prokaryotes

Cyanobacteria, purple bacteria and green-sulphur bacteria are the 3 examples of photosynthesizing prokaryotes.

Explanation:

The cyanobacteria are also called as oxygenic photoautotrophs. Although prokaryotes do not have well-defined chloroplast instead they have chlorophyll bound in vesicles.

They take energy from sunlight, absorb Carbon dioxide to make food and release oxygen in the process.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds