The reaction of photosynthesis produces oxygen and atp

The light reaction of photosynthesis produces oxygen and ATP.

they float because they are less dense than the water itself

something denser than water, like a rock, will sink to the bottom

weathering - colorado river carves land in arizona to form the grand canyon. cracks form in a sandstone wall surrounding a house. a marble statue near the science museum is changing color due to rainfall

erosion - after a rainstorm, soil and rock piees litter the roadways. the sand dunes in the sahara desert are changing shape.

here's your answer.