Nickel
Definition and meaning of Nickel in chemistry.
Nickel is a silvery-white lustrous transition metal with the chemical symbol Ni and atomic number 28. It is a hard and ductile element that is highly resistant to corrosion and oxidation, making it invaluable in metallurgical applications.
In more detail
Belonging to the iron group of transition metals in group 10 of the periodic table, nickel is naturally magnetic at or near room temperature, a property it shares with iron and cobalt. It typically exhibits an oxidation state of +2, though compounds containing nickel in multiple oxidation states such as +3 and +4 are also well documented in chemical literature. The metal occurs naturally in meteoric iron and various mineral ores like pentlandite and garnierite, predominantly concentrated deep within the Earth's core alongside iron. Because of its extremely slow rate of oxidation at room temperature, it maintains a highly polished, reflective surface and is widely used for electroplating other susceptible metals to protect them from tarnishing and degradation. It forms numerous valuable alloys, particularly austenitic stainless steels, which heavily rely on its high melting point, toughness, and enduring chemical stability under extreme environmental conditions.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Ni |
| Atomic number | 28 |
| Atomic mass | 58.693 u |
| Category | Transition Metal |
| State at room temperature | Solid |
| Melting point | 1455 °C (2651 °F) |
| Discovery year | 1751 |
Nickel is extensively alloyed with iron and chromium to manufacture stainless steel used in kitchen appliances and industrial piping.
Frequently asked questions
Is nickel toxic to humans?
While essential in trace amounts for some organisms, excessive exposure to nickel compounds can be toxic and may cause allergic contact dermatitis in sensitive individuals.
Why is nickel used in coins?
Its resistance to corrosion, combined with its durability and attractive silvery appearance, makes it ideal for manufacturing long-lasting metallic currency.