Mainly Carbon dioxide enters. Some water can enter,but majority of water leaves through them
If you mean "what is observed when carbon dioxide enters lime water" then lime water, or calcium carbonate (CaCO3) absorbs carbon dioxide (CO2) to form a white precipitate or "milky" solution that is semitransparent.
Both carbon dioxide and oxygen found in air enters through the stomata. More at Link
osmosis
The raw materials of photosynthesis that enters the leaf through the stomates or stomata is H2O or water
Carbon monoxides are particles of carbon which enters the air when coal and wood are burned.
oxygen enters and glucose is released... follow on instagram @nailsbyisis
Carbon enters the biotic part of the ecosystem through the process of photosynthesis, in which carbon dioxide from the atmosphere and water react to produce glucose (C6H12O6) and oxygen.
combustion
Air
Carbon enters a consumer contained in the complex molecules of the food the consumer eats. Carbon exits the consumer as a gas called Carbon Dioxide - which is usually breathed out.
Carbon enters into livings systems differently, depending on the organism. With plants, carbon primarily enters as carbon dioxide during photosynthesis . In animals carbon is taken up through food.