One carbon atom has 4 valence electrons. Hope this helps
The palisade cells are the main site of photosynthesis, as they have many more chloroplasts than spongy mesophyll, and also have several adaptations to maximizes photosynthesis efficiency. Large Vacuole restricts chloroplasts to a later near outside of the cell where they can be reached by light more easily.
The three types of chemical bonds are Ionic, Covalent, and Metallic
Producers are green plants or photosynthetic organisms that are the basis for the other living parts of any ecosystem. Producers need to have access to light to produce food. Few producers will be found deep below a lakes surface simply because the deeper you travel under water the less light penetrates those deeper layers.