Nickel
Nickel (Ni, atomic number 28) is a Period 4 transition metal (d-block, 58.693 u). Abundant in iron meteorites and Earth's core. Essential cofactor in jack-bean urease (hydrolyzing urea), bacterial [NiFe]-hydrogenases, and Cofactor F430 in archaeal me
Nickel is a chemical element on the periodic table with the atomic symbol Ni, atomic number 28, and standard atomic weight 58.693 u. Classified as a Transition Metal within Group 10 and Period 4 (d-block), nickel possesses a ground-state electron configuration of [Ar] 3d8 4s2 distributed across 4 concentric Bohr electron shells (2 · 8 · 16 · 2) with 2 outer-shell electrons. Abundant in iron meteorites and Earth's core. Essential cofactor in jack-bean urease (hydrolyzing urea), bacterial [NiFe]-hydrogenases, and Cofactor F430 in archaeal methanogenesis.
⚛️ Interactive Periodic Table Lab: Explore Nickel (Ni, Z = 28) in the CRV Science Dynamic Periodic Table & Bohr Orbital Lab to visualize its animated 2 · 8 · 16 · 2 electron shells, simulate live phase transitions from 0 K to 6,000 K, and compare periodic heatmaps across all 118 IUPAC elements.
Atomic Structure and Periodic Trends: How Do Quantum Orbitals Define Nickel?
Electron Shell Architecture and Ground-State Configuration
A neutral atom of nickel contains 28 protons in its atomic nucleus balanced by 28 electrons occupying quantized atomic orbitals. In the Bohr-Sommerfeld and quantum-mechanical orbital models, these electrons populate 4 principal energy shells (K (n=1): 2e−, L (n=2): 8e−, M (n=3): 16e−, N (n=4): 2e−), terminating in the four-lobed d-orbital manifold (azimuthal quantum number l = 2) with ground-state configuration [Ar] 3d8 4s2. Removing the most loosely bound valence electron from an isolated gaseous nickel atom requires a first ionization energy of 737 kJ/mol, while its tendency to attract shared bonding electrons is quantified by a Pauling electronegativity of 1.91.
Periodic Table Position and Neighboring Elements
Within the periodic table, Nickel occupies Period 4, Group 10 of the d-block (Transition Metals). Along Period 4, it is flanked by Cobalt (Co, Z = 27) and Copper (Cu, Z = 29). Vertically within its periodic family, Nickel shares valence orbital symmetry and homologous chemical trends with Palladium (Pd), Platinum (Pt), Darmstadtium (Ds). Learners can interactively compare Nickel's orbital radii, ionization energy, and Pauling electronegativity against all neighboring elements in the Dynamic Periodic Table Lab.
Physical and Thermodynamic Properties: How Does Nickel Behave Across Temperature Regimes?
Standard Phase, Melting Point, and Boiling Point Dynamics
At standard ambient temperature and pressure (298.15 K / 25 °C, 1 atm), elemental nickel exists as a crystalline solid. As thermal energy increases, its crystal or molecular lattice undergoes solid-to-liquid fusion at a melting point of 1,728 K (+1454.85 °C / +2650.7 °F) and transitions to the vapor phase at a normal boiling point of 3,186 K (+2912.85 °C / +5275.1 °F), spanning a liquid thermodynamic range of 1458 K. In the CRV Science Dynamic Periodic Table, dragging the live temperature slider between absolute zero (0 K) and solar-photosphere temperatures (6,000 K) dynamically tracks Nickel's state transitions in real time alongside enthalpy and entropy phase equilibria.
Quantitative Atomic and Thermodynamic Parameter Matrix
| Parameter | Quantitative Value / Formula | Physical / Quantum Basis | Comparative Context in Group 10 / Period 4 |
|---|---|---|---|
| Atomic Number & Symbol | Z = 28 (Ni) | 28 nuclear protons; nuclear charge +28e | Located in Period 4, Group 10 (d-block) |
| Standard Atomic Weight | 58.693 u (g/mol) | Abundance-weighted isotopic nucleon mass | ~31 neutrons in dominant/reference mass number |
| Electron Configuration | [Ar] 3d8 4s2 | Shells: 2 · 8 · 16 · 2 (2 outer-shell e−) | Transition Metals valence orbital architecture |
| Electronegativity & Ionization | χ = 1.91; IE1 = 737 kJ/mol | Pauling bond polarity scale & first valence ionization enthalpy | Governs covalent vs. ionic bond character |
| Melting & Boiling Points | MP: 1728 K; BP: 3186 K | Cohesive lattice energy and intermolecular forces | STP (298 K) phase: SOLID (Liquid range: 1458 K) |
| Principal Oxidation States | +2, +3 | Valence electron donation, sharing, or acceptance | Discovered / First Isolated: 1751 |
Chemical Reactivity, Bonding, and Oxidation States: How Does Nickel Form Compounds?
Characteristic Oxidation States and Coordination Chemistry
As a d-block transition metal, partially filled (n−1)d orbitals lie close in energy to the outermost ns subshell, enabling variable oxidation states, d–d electronic transitions, coordination complex formation, and heterogeneous or metalloenzymatic redox catalysis. In chemical compounds, nickel exhibits characteristic oxidation states of +2, +3. Depending on the electronegativity difference (Δχ) of its bonding partners—such as Oxygen (χ = 3.44), Fluorine (χ = 3.98), Chlorine (χ = 3.16), Nitrogen (χ = 3.04), Carbon (χ = 2.55), or Hydrogen (χ = 2.20)—nickel forms redox-specific oxides, halides, hydrides, or coordination complexes governed by Gibbs free energy (ΔG = ΔH − TΔS).
Nucleosynthesis, Discovery History, and Elemental Origins
First identified or isolated in 1751, Nickel carries a distinct cosmological and geochemical signature. With atomic number Z = 28 beyond the iron-56 binding-energy peak, nickel is synthesized astrophysically via neutron-capture nucleosynthesis—combining slow neutron capture (the s-process in asymptotic giant branch stars) and rapid neutron capture (the r-process in neutron-star mergers and core-collapse supernovae).
Biological Role and Scientific Applications: Why Is Nickel Important in Nature and Technology?
Biochemical Classification: Specialized / Ultra-Trace Bio-Element
In comparative biochemistry and systems physiology, Nickel is classified as Specialized / Ultra-Trace Bio-Element. Utilized by specialized lineages (e.g., diatom silica frustules, tunicate vanabins, methanogen nickel cofactors, nitrogenase). Across terrestrial and marine ecosystems, its chemical speciation interacts with enzymes, biogeochemical cycle, phytoplankton, archaea.
Key Mechanistic Functions and Technological Uses
Abundant in iron meteorites and Earth's core. Essential cofactor in jack-bean urease (hydrolyzing urea), bacterial [NiFe]-hydrogenases, and Cofactor F430 in archaeal methanogenesis. Researchers and students can further investigate Nickel's functional role alongside all 118 elements by launching the Interactive Periodic Table & Element Detective Lab on CRV Science Learn.
Frequently Asked Scientific Questions
What is the electron configuration and valence shell structure of Nickel (Ni)?
Nickel (atomic number Z = 28) has the ground-state electron configuration [Ar] 3d8 4s2, distributing its 28 electrons across 4 shells as 2 · 8 · 16 · 2. Its outermost shell contains 2 electrons, placing Nickel in Group 10, Period 4 (d-block) as a member of the Transition Metals. You can watch these 28 electrons orbit the nucleus in real time in the Dynamic Periodic Table Bohr Lab.
What phase of matter is Nickel at room temperature, and when does it melt or boil?
At standard room temperature (298 K / 25 °C) and 1 atm pressure, Nickel is a crystalline solid. It melts at 1,728 K (+1454.85 °C / +2650.7 °F) and boils at 3,186 K (+2912.85 °C / +5275.1 °F). Using the 0–6,000 K temperature slider in the Interactive Periodic Table, you can observe Nickel's exact solid, liquid, and gas transitions relative to all other elements.
How does Nickel function in biochemistry, materials science, and technology?
Abundant in iron meteorites and Earth's core. Essential cofactor in jack-bean urease (hydrolyzing urea), bacterial [NiFe]-hydrogenases, and Cofactor F430 in archaeal methanogenesis. In biological systems, it is categorized under Specialized / Ultra-Trace Bio-Element, with principal oxidation states of +2, +3 and a first ionization energy of 737 kJ/mol.