Potassium is vital to the plants growth. Potassium can be absorbed as a liquid only, the potassium is responsible for the production of proteins and sugars for energy and growth.
K+ ions
Potassium hydrocarbonate is a source of carbon dioxide and aquatic plants can absorb it to use for photosynthesis.
Nitrogen is needed for all life forms, including plants. Plants absorb nitrogen from soil through their roots in the form of nitrate and ammonia.
The difference is that flowering plants have cells and absorb sunlight, bryophytes do not absorb sunlight or form photsynthesis.
Potassium
Potassium hydroxide is a strong alkali and is highly soluble in water. It reacts with acids to form potassium salts. It is often used in experiments to absorb carbon dioxide present in the system.
Nitrogen fixing bacteria along and on the roots of plants converts gaseous nitrogen into a form that plants can absorb.
Plants absorb mineral nutrients by way of ions in the soil. This is basically the case with how all plants get their nutrients besides sunlight. The process takes place at the atomic level.
There are traces of metals (or to be precise, metal ions) in all plants - they absorb them from the soil and the air they grow in. Bananas contain radioactive potassium!
It will not absorb it but will congeal with it to create a sticky mess!
Plants absorb carbon dioxide during photosynthesis.
KOH (melted) + CO = HCOOK (potassium formate)
Potassium Hydroxide can be used to absorb carbon dioxide from the air.