You notice greens gum floating on the surface of a pod. how can you tell whether these organisms are plants?

The greens gum that is floating above the pond is called algae. Algae is a plant that quickly reproduces and it floats above the pond to reach the Sun in order to do photosynthesis. Through photosynthesis and chlorophyll inside of an plant, together to make the algae look green, which is why it is an plant.