Number of essential elements in plants is

There are about 17 mineral elements which are considered as essential for the plants. They can be grouped into two categories: micronutrients and macronutrients. Macronutrients are present in plants in easily detectable quantities and are 10 in number. They include- carbon, oxygen, hydrogen, nitrogen, iron, potassium, calcium, phosphorus, magnesium and sulphur. They are generally required to build up the plant body, regulate osmotic concentration and take part in biochemical reactions. Micronutrients are present in plants in minute quantities and are 7 in number. They include chlorine, manganese, boron, zinc, copper, molybdenum and nickel. They are generally required in the functioning of enzymes , as cofactors or metal activators.