deposition mechanism including: (1) Atomic hydrogen mechanism, (2) Hydride transfer mechanism, (3) Electrochemical mechanism, and (4) Metal hydroxide mechanism which will be discussed in the process section. The four classical examples of electroless deposition are often linked to industrial processes. Tollen's reaction deposits a uniform metallic silver layer via ED on glass which is referred to a silvering mirrors. This reaction is used to test for aldehydes as a basic solution of silver nitrate. This reaction is often used as crude method used in chemistry demonstrations for the oxidation of an aldehyde to carboxylic acid, and the reduction of the silver cation into elemental silver. Electroless deposition is an important process for industrial, and laboratory reactions in their quest to study the kinetics and test proposed mechanisms. Electroless deposition vs other plating methods Electroless deposition is an important process in the electronic industry for metallization of substrates. Other metallization of substrates also include physical vapor deposition (PVD), chemical vapor deposition (CVD), and electroplating which produce thin metal films but require high temperature, vacuum, and a power source respectively. This class is contrasted with electroplating processes, where the reduction is achieved by an externally generated electric current. Electroplating suffers from uneven current density due to the effect of substrate shape on the electrical resistance of the bath. These defects include loss of adhesion, contamination, and rigidity of the structure. Electroless deposition is advantageous in comparison to PVD, CVD, and electroplating deposition methods because it can be performed at ambient conditions. The plating method for Ni-P, Ni-Au, Ni-B, and Cu baths are distinct; however, the processes involve the same approach. The electroless deposition process is defined by four steps show in Fig.1 (1) Pretreatment or functionalization of the substrate cleans the surface of the substrate to remove any contaminants, determines the porosity of the elemental metal deposition, and the initiation site of the deposition. (2) Sensitization is an activator ion that can reduce the active metal in the deposition bath. (3) Activation accelerates the deposition of the active metal in the deposition bath. (4) Electroless deposition is the process by which metal cation is reduced to elemental metal The electroless deposition process is based on the principle of redox reactions in which electrons are transferred during a chemical reaction. The chemical bath thus has a cathodic and anodic reaction in this one-pot reaction. The design of the deposition process includes carefully chosen