Because it's less dense than liquid water.
The reactants for photosynthesis are light energy, water, carbon dioxide and chlorophyll, while the products are glucose (sugar), oxygen and water.
Yes ,this is true.
For example if you want to count the amount of money available to you and you have 300 in savings but you owe your friend 450, then your total amount of money will actually be:
-150
which means that you have debt. - a negative number represents debt.
