Why is NH3 tetrahedral?

Why is NH3 tetrahedral?

NH3 is a chemical symbol for the compound ammonia. This chemical compound is basically formed from the basic elements of nitrogen and hydrogen, in the absence of water. As early as the 8th century, salts of ammonia have already use by Muslim alchemists and, during the 13th century, this substance was use by European alchemists to alter colors of vegetable dyes. In this modern era, it is a significant nutritional substance that acts as a forerunner for providing essential nutrients to certain food and fertilizers. It was also studied that ammonia is used to synthesize certain pharmaceutical drugs. However, because of this compound’s corrosive property, its increased ability to destroy other materials that come in contact with such substance is deemed to be highly dangerous and can cause detrimental effects. Most ammonia compounds are components of many cleaning materials.
Other names of ammonia are hydrogen nitride, trihydrogen nitride and Nitro-Sil. It is named as trihydrogen nitride because this represents the molecular shape of the compound. In ammonia, there is one nitrogen atom and three hydrogen molecules. Each of these hydrogen molecules is attached to the nitrogen atom. However, there is one free electron since there are only 3 hydrogen molecules that form significant bonds. Thus, the compound of ammonia is in a trigonal pyramidal shape or in a tetrahedral sphere because as atoms form bonds at 107.8 degrees, 4 pairs of electrons formed by the 5 valence electrons of nitrogen and the 3 electrons of hydrogen are distributed equally around the molecule. Thus, it gives the compound a tetrahedral shape, otherwise known as trigonal pyramidal shape.
Because of the properties that ammonia possesses, it is considered an alkaline substance since the lone pair of electrons allows it to be a proton acceptor and an electron donor.