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Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to its heavier homologues strontium and barium. It is the fifth most abundant element in Earth's crust, and the third…
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metal used also isotopes element strontium lime bone compounds barium aluminium stable chemical magnesium 48ca high ca2 40ca carbon oxygen
| Subject | Predicate | Object | Confidence | Src |
|---|---|---|---|---|
| Calcium | 40Ca | 96.9% | 1.00 | infobox |
| Calcium | 41Ca | trace | 1.00 | infobox |
| Calcium | 42Ca | 0.647% | 1.00 | infobox |
| Calcium | 43Ca | 0.135% | 1.00 | infobox |
| Calcium | 44Ca | 2.09% | 1.00 | infobox |
| Calcium | 45Ca | synth | 1.00 | infobox |
| Calcium | 46Ca | 0.004% | 1.00 | infobox |
| Calcium | 47Ca | synth | 1.00 | infobox |
| Calcium | 48Ca | 0.187% | 1.00 | infobox |
| Calcium | Appearance | dull gray, silver; with a pale yellow tint | 1.00 | infobox |
| Calcium | at T (K) | 864 | 1.00 | infobox |
| Calcium | Atomic number (Z) | 20 | 1.00 | infobox |
| Calcium | Atomic radius | empirical: 197 pm | 1.00 | infobox |
| Calcium | Block | s-block | 1.00 | infobox |
| Calcium | Boiling point | 1757 K (1484 °C, 2703 °F) | 1.00 | infobox |
| Calcium | Brinell hardness | 170–416 MPa | 1.00 | infobox |
| Calcium | Bulk modulus | 17 GPa | 1.00 | infobox |
| Calcium | CAS Number | 7440-70-2 | 1.00 | infobox |
| Calcium | Covalent radius | 176±10 pm | 1.00 | infobox |
| Calcium | Crystal structure | face-centred cubic (fcc) (cF4) | 1.00 | infobox |
| Calcium | Density (at 20° C) | 1.526 g/cm3 | 1.00 | infobox |
| Calcium | Discovery and first isolation | Humphry Davy (1808) | 1.00 | infobox |
| Calcium | Electrical resistivity | 33.6 nΩ⋅m (at 20 °C) | 1.00 | infobox |
| Calcium | Electron configuration | [Ar] 4s2 | 1.00 | infobox |
| Calcium | Electronegativity | Pauling scale: 1.00 | 1.00 | infobox |
| Calcium | Electrons per shell | 2, 8, 8, 2 | 1.00 | infobox |
| Calcium | Group | group 2 (alkaline earth metals) | 1.00 | infobox |
| Calcium | Heat of fusion | 8.54 kJ/mol | 1.00 | infobox |
| Calcium | Heat of vaporisation | 154.7 kJ/mol | 1.00 | infobox |
| Calcium | Ionisation energies | 1st: 589.8 kJ/mol | 1.00 | infobox |
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