Answer:
Any substance that cannot be decomposed into simpler substances by ordinary chemical processes.
Another definition:
An element is the simplest pure substance which can neither be split nor built up from other simpler substances by chemical reaction
Answer:
Chlorophyll
Explanation:
Photosynthesis is the process through which plant cells use carbon dioxide & water to create oxygen & energy rich organic compounds. They do so by converting sunlight ie light energy into chemical energy. This is possible due to presence of chlorophyll in them. Animals can't do so, as they dont have chlorophyll.
Any of the basic mechanical devices for applying a force, such as an inclined plane, wedge, or lever.