Hydroponics is $............$

What is hydroponics?

Which of the following statements are not correct in reference to hydroponics?
$I.$ It determines the mineral nutrients essential for the plants.
$II.$ The hydroponics involves the culture of plants in a soil with,defined mineral solution.
$III.$ Hydroponics requires purified water with non-defined mineral nutrient salts.
$IV.$ In the hydroponics technique,plants are grown in sandy soil with nutrient solution.
$V.$ By this method,essential elements required for the growth of plants can be identified and their deficiency symptoms can also be discovered.
Choose the correct options.

Name the technique used by researchers to explore plant nutrient deficiencies.

Hydroponics is a technique of growing plants in a

Who demonstrated the concept of hydroponics for the first time?