30ZnZinc65.38 u
Zinc (Zn)
Zinc is a transition metal with atomic number 30, in period 4 and group 12 of the periodic table. Its atomic mass is 65.38 u and its electron configuration is [Ar] 3d¹⁰ 4s². Solid at 25 °C.
Key facts
| Atomic number | 30 |
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| Atomic mass | 65.38 u |
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| Category | Transition Metal |
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| Period | 4 |
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| Group | 12 |
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| Block | d |
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| Electron configuration | [Ar] 3d¹⁰ 4s² |
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| Electrons per shell | 2, 8, 18, 2 |
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| Electronegativity (Pauling) | 1.65 |
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| Oxidation states | −2, +1, +2common in bold |
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| State at 25 °C | Solid |
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| Melting point | 692.68 K419.53 °C |
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| Boiling point | 1180 K906.85 °C |
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| Density | 7.14 g/cm³ |
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Atomic properties
| First ionization energy | 9.394 eV |
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| Electron affinity | 0 kJ/mol |
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| Atomic radius | 138 pm |
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| Covalent radius | 122 pm |
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| Van der Waals radius | 139 pm |
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| Common ions | Zn²⁺ |
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| Protons, neutrons, electrons | 30, 35, 30 |
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Physical and thermal properties
| Molar volume | 9.16 cm³/mol |
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| Heat of fusion | 7.35 kJ/mol |
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| Heat of vaporization | 119 kJ/mol |
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| Specific heat | 388 J/(kg·K) |
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| Thermal conductivity | 120 W/(m·K) |
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| Thermal expansion | 3.02 × 10⁻⁵ K⁻¹ |
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| Mohs hardness | 2.5 |
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| Young’s modulus | 108 GPa |
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| Crystal structure | Simple hexagonal |
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| Magnetic type | Diamagnetic |
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Identification and history
| CAS number | 7440-66-6 |
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| Latin name | Zincum |
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| Discovered by | Known since antiquity |
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| Named by | --- |
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Natural isotopes
| Isotope | Mass (u) | Abundance |
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| 64Zn | 63.929142 | 49.17 % |
| 66Zn | 65.926034 | 27.73 % |
| 67Zn | 66.927127 | 4.04 % |
| 68Zn | 67.924844 | 18.45 % |
| 70Zn | 69.925319 | 0.61 % |
Data checked against PubChem (NIH), IUPAC, the NIST Atomic Spectra Database and the IAEA (NUBASE and AME), the same data you see in the app.
A dash (---) means there is no reliable published measurement. The app never makes one up.
See Zinc in the app
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Periodic Table