Answer:
In a chemical reaction, there is a change in the composition of the substances in question; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition. Although we call them physical "reactions," no reaction is actually occurring.
When the little fish die they sink to the bottom, and after time the skeletons build up on top of each other.
Answer:
The three types of organisms in an ecosystem are producers, consumers, and decomposers.
Producers get their energy by using sunlight to make their own food from water and carbon dioxide through photosynthesis.
Consumers get their energy by eating plants and animals for food as they cannot make their own food.
Decomposers get their energy by eating/scavenging and breaking down dead and decaying plant and animal bodies.
Hope that helps.