2P2 28 Wang Jiaxin

Ammonium
The ammonium (more obscurely: aminium) cation is a positively charged polyatomic cation with the chemical formula NH+
4. It is formed by the protonation of ammonia (NH₃). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary ammonium cations (N⁺R₄), where one or more hydrogen atoms are replaced by organic radical groups (indicated by R).
In the substitutive nomenclature NH₄⁺ is denoted by the name azanium instead of ammonium.
Formation
Formation of ammonium compounds can also occur in the vapor phase; for example, when ammonia vapor comes in contact with hydrogen chloride vapor, a white cloud of ammonium chloride forms, which eventually settles out as a solid in a thin white layer on surfaces.
The conversion of ammonium back to ammonia is easily accomplished by the addition of strong base.

Carbon-nitrogen bond

A carbon-nitrogen bond is a covalent bond between carbon and nitrogen and is one of the most abundant bonds in organic chemistry and biochemistry.^[1]
Nitrogen has five valence electrons and in simple amines it is trivalent, with the two remaining electrons forming a lone pair. Through that pair, nitrogen can form an additional bond to hydrogen making it tetravalent and with a positive charge in ammonium salts. Many nitrogen compounds can thus be potentially basic but its degree depends on the configuration: the nitrogen atom in amides is not basic due to delocalization of the lone pair into a double bond and in pyrrole the lone pair is part of an aromatic sextet.
Similar to carbon-carbon bonds, these bonds can form stable double bonds, for instance imines and triple bonds such as nitriles. Bond lengths range from 147.9 pm for simple amines to 147.5 pm for C-N= compounds such as nitromethane to 135.2 pm for partial double bonds in pyridine to 115.8 pm for triple bonds as in nitriles.
A CN bond is strongly polarized towards nitrogen (electronegativity for C and N is 2.55 and 3.04, respectively) and subsequently molecular dipole moments can be high: cyanamide 4.27 D, diazomethane 1.5 D, methyl azide 2.17, pyridine 2.19. For this reason many compounds containing CN bonds are water-soluble.

Properties of Carbon
Carbon  is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. There are three naturally occurring isotopes, with ¹²C and ¹³C being stable, while ¹⁴C is radioactive, decaying with a half-life of about 5730 years. Carbon is one of the few elements known since antiquity. The name "carbon" comes from Latin carbo, coal.

Properties of Nitrogen 

Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere. The element nitrogen was discovered as a separable component of air, by Scottish physician Daniel Rutherford, in 1772.