What is the relationship between starch in plants? .

Plant photosynthesis and energy creation are complex processes involving carbon dioxide, water and sunlight, facilitated by multiple enzymes to create the basic sugar called glucose. Much of the glucose plants produce is immediately metabolized into different forms of energy that plants use to grow and reproduce. The portions of glucose that are not immediately converted to energy are converted to complex sugar compounds, called starches. These are produced after the photosynthesis cycle. Plants then store starches for future energy needs or use them to build new tissues.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds