Give the formula for borax.

Hint :The other names of borax are sodium borate, sodium tetraborate or disodium tetraborate. It is a very soft and colorless compound of boron. It is also dissolved in water. Anhydrous and decahydrate salt and pentahydrate salt are the main forms of borax. The most common in all of these is borax decahydrate. We will discuss in detail below.

Complete Step By Step Answer:
The most common form of borax that is borax decahydrate has $ 4 $ boron atoms, $ 17 $ oxygen atoms, $ 2 $ sodium atoms, and $ 20 $ hydrogen atoms. The chemical formula for borax is $ N{a_2}{B_4}{O_7}.10{H_2}O $ or we can also write it as $ N{a_2}{B_4}{O_5}{\left( {OH} \right)_4}.8{H_2}O $ and its molecular formula is $ {H_{20}}{B_4}N{a_2}{O_{17}} $ . Borax is a naturally found substance. It is found in evaporite deposits that are produced by the recurrent evaporation of seasonal lakes. It is then purified by recrystallization. Boron is mainly synthesized from boron compounds. Borax is also present in powdered form which is soft, colorless and readily dissolves in water. It is white in color when it is present in powdered form. The borax which is used commercially is partly dehydrated.

Note :
Borax has a great use in the agriculture field. When we convert water molecules to hydrogen peroxide $ \left( {{H_2}{O_2}} \right) $ it helps to clean and destroy unwanted pests. One point you should keep in your mind as it is used commercially so you should take care that it cannot be swallowed. If you inhale or swallow it then both severe poisoning and organ injury can take place. It includes vomiting, eye irritation, skin rash, nausea and respiratory effects also.