Photosynthesis uses radiant energy from light converting it into . The process requires light, water, and to produce sugars. Oxygen is a byproduct. Life on earth depends on photosynthesis.

Explanation:

Photosynthesis is the process through which plants, some bacteria, and some others organisms  made their food by the use of  energy from sunlight and convert it into chemical energy to  produce sugar. The conversion of sunlight energy into usable chemical energy, is held by chlorophyll. The photosynthetic process uses water  as an electron donor and releases the oxygen.

The overall reaction of photosynthesis is:

6 molecules of water + 6 six molecules of carbon dioxide with the help of light, produce one molecule of sugar + six molecules of oxygen

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.