Cadmium
by Yogi P - October 23, 2023
Cadmium: A Heavy Metal Element
Cadmium is a heavy metal element discovered in 1817 by German chemists Friedrich Stromeyer and Karl Samuel. It is silvery-white in colour and is highly toxic when inhaled. Cadmium is present in small amounts in the environment, and in its elemental form, it is not harmful.
Most of us are familiar with cadmium in batteries, pigments, and plastic stabilizers – all of which are essential to everyday life and technology.
History and Discovery of Cadmium
Cadmium was discovered by Stromeyer and Samuel in 1817 while they were studying the compounds in zinc carbonate. They separated out a chalky-white oxide that they named “kadmium,” which was derived from the Greek word “kadmeia” meaning “calamine stone,” a zinc-rich ore.
They later discovered that the oxide was actually an element of its own, and they changed the correct spelling to “cadmium.”
In the 1880s, cadmium was used in light bulbs and theater lights due to its ability to emit ultraviolet radiation. In the 1930s, chemists began to develop cadmium-based batteries, pigments, and plastic stabilizers.
Properties of Cadmium
- Atomic number: 48
- Symbol: Cd
- Atomic mass: 112.41 amu
- Melting point: 320.9 °C
- Boiling point: 765 °C
- Density: 8.65 g/cm³
- Valence electrons: 2
Uses of Cadmium
| Used in | Description |
|---|---|
| Batteries | Cadmium is commonly used in rechargeable nickel-cadmium (Ni-Cd) batteries due to its low cost and high energy capacity. |
| Plastic Stabilizers | Cadmium is added in small amounts to polyvinyl chloride (PVC) plastic to strengthen it and improve heat stability. |
| Pigments | Cadmium is used to create yellow, orange, and red pigments in both industrial paints and arts and crafts. |
| Solar Cells | Cadmium is an important component of some solar cells, helping convert sunlight into energy and making them more efficient. |
| Electrical Components | Cadmium is used in electronics and electrical components due to its high conductivity and low reactivity. |
Safety Precautions
Cadmium is an essential element in today’s life, though it is toxic in large quantities. Therefore, it is important to practice safety measures such as wearing protective clothing and gloves when handling cadmium, storing it in well-ventilated and designated areas, and disposing of it properly.
Conclusion
Cadmium is an essential element that plays an important role in batteries, plastic stabilizers, pigments, solar cells, and electrical components. Although it is toxic in large quantities, as long as safety precautions are followed, it is a beneficial metal that is used in a variety of applications around the world.
