Cadmium is a metal that is usually found underground along with zinc. It is so soft that it can be cut with a knife. It is a transition metal. It refers to metals that are found between group 2 and group 13 in the periodic table.


Physical and chemical properties:

Cadmium is a lustrous metal with a light black color. It is a soft metal so soft that it can be cut with a knife. Its melting and boiling points are 321 degrees Celsius and 765 degrees Celsius respectively. Its atomic number is 48 and is denoted by Cd.

Cadmium is affected by humid air, but the rate of this effect is very slow. It is not affected by water, i.e. it does not dissolve in water (chemical reaction). However, it is soluble in all types of acids. (chemical interaction) may occur.


Discovery:

Cadmium was discovered in 1817 by Friedrich Stromeyer.


Cadmium production:

Granokite is a mineral in which cadmium is found in large quantities. However, it is mostly obtained commercially as a by-product in the refining of zinc.



Cadmium and electroplating:

As we know that steel can rust easily and it can be protected from rust if a layer of other metals is coated on it using electric current. This process is called electroplating technique. In both the metals i.e. the metal to be plated and the metal to be coated, are immersed in an electrolyte solution. When a current is passed through this solution, a layer of the other metal is deposited on the desired metal. Until when cadmium was widely used in electroplating of steel. In the 1960s, due to the negative effects of cadmium on the environment, the use of cadmium for this purpose has been reduced. Because we know that cadmium is a toxic metal. It dissolves in the air and soil and causes damage to both humans and the environment.


Nickel cadmium batteries:

The main use of cadmium is in nickel-cadmium batteries. It is used as an electrode in nickel-cadmium batteries in the alloy state. Nickel-cadmium (NiCd) batteries are mostly used in devices such as toys, flashlights and power tools. These 1.5 volt batteries are relatively cheap, can be charged and discharged hundreds of times.

NiCd batteries are often cited as requiring NiCd batteries to be fully discharged before charging or the amount of charge they can store (and their effective lifespan) can be greatly reduced. . Opinions vary on whether this is true and, if so, why it happens, but as a rule of thumb, it's good practice to regularly fully discharge batteries and then recharge them. Another problem with NiCd batteries is the cadmium metal used in them. Cadmium is a toxic metal like mercury and lead. Therefore, they should be recycled or disposed of in the open environment. should or should be stored. Due to the negative effects of nickel batteries on the environment and low, they are now mostly replaced by other batteries such as nickel hydride and lithium ion batteries. These batteries weigh less than nickel cadmium,


Effects on health:

Cadmium is a toxic metal like lead and mercury. Although there is no clear description of the effects of cadmium on the human body, it is said that it can affect various organs of the human body such as the heart and kidneys. Apart from this, it can increase blood pressure and cause cancer.

Therefore, we need to recycle cadmium-containing products such as batteries, instead of throwing them in the open environment. Because it can dissolve in soil and water and get into our food and water, which can affect human health. Adverse effects can occur. People who work in factories where cadmium is produced or used should take extra precautions because its powder can enter the body through the air, causing a number of problems.