iron vs calcium vs potassium

iron (chemical element) | calcium (chemical element) | potassium (chemical element)

Periodic table location

Images

| iron | calcium | potassium atomic symbol | Fe | Ca | K atomic number | 26 | 20 | 19 short electronic configuration | [Ar]4s^23d^6 | [Ar]4s^2 | [Ar]4s^1 Aufbau diagram | 3d 4s | 4s | 4s block | d | s | s group | 8 | 2 | 1 period | 4 | 4 | 4 atomic mass | 55.845 u | 40.078 u | 39.0983 u half-life | (stable) | (stable) | (stable)

| iron | calcium | potassium phase at STP | solid | solid | solid melting point | 1538 °C | 842 °C | 63.38 °C boiling point | 2861 °C | 1484 °C | 759 °C critical temperature | (unknown) | | 2223 K critical pressure | (unknown) | | 16 MPa molar heat of fusion | 13.8 kJ/mol | 8.54 kJ/mol | 2.33 kJ/mol molar heat of vaporization | 347 kJ/mol | 155 kJ/mol | 76.9 kJ/mol specific heat at STP | 449 J/(kg K) | 631 J/(kg K) | 757 J/(kg K) (properties at standard conditions)

| iron | calcium | potassium density | 7.874 g/cm^3 | 1.55 g/cm^3 | 0.856 g/cm^3 liquid density | 6.98 g/cm^3 | 1.378 g/cm^3 | 0.828 g/cm^3 molar volume | 7.092 cm^3/mol | 25.86 cm^3/mol | 45.7 cm^3/mol Mohs hardness | 4 (≈ fluorite) | 1.75 (between gypsum and talc) | 0.4 (between talc and gypsum) Vickers hardness | 608 MPa | | Brinell hardness | 490 MPa | 167 MPa | 0.363 MPa bulk modulus | 170 GPa | 17 GPa | 3.1 GPa shear modulus | 82 GPa | 7.4 GPa | 1.3 GPa Young's modulus | 211 GPa | 20 GPa | Poisson ratio | 0.29 | 0.31 | tensile yield strength | 50 MPa | | sound speed | 4910 m/s | 3810 m/s | 2000 m/s thermal expansion | 1.18×10^-5 K^(-1) | 2.23×10^-5 K^(-1) | thermal conductivity | 80 W/(m K) | 200 W/(m K) | 100 W/(m K) (properties at standard conditions)

| iron | calcium | potassium electrical type | conductor | conductor | conductor resistivity | 9.7×10^-8 Ω m (ohm meters) | 3.4×10^-8 Ω m (ohm meters) | 7×10^-8 Ω m (ohm meters) electrical conductivity | 1×10^7 S/m (siemens per meter) | 2.9×10^7 S/m (siemens per meter) | 1.4×10^7 S/m (siemens per meter) magnetic type | ferromagnetic | paramagnetic | paramagnetic volume magnetic susceptibility | | 2.139×10^-5 | 5.74×10^-6 mass magnetic susceptibility | | 1.38×10^-8 m^3/kg (cubic meters per kilogram) | 6.7×10^-9 m^3/kg (cubic meters per kilogram) molar magnetic susceptibility | | 5.531×10^-10 m^3/mol (cubic meters per mole) | 2.62×10^-10 m^3/mol (cubic meters per mole) Curie point | 1043 K (kelvins) | | work function | (4.67 to 4.81) eV | 2.87 eV (Polycrystalline) | 2.29 eV (Polycrystalline) threshold frequency | (1.129×10^15 to 1.163×10^15) Hz (hertz) | 6.94×10^14 Hz (hertz) | 5.537×10^14 Hz (hertz) color | (gray) | (silver) | (silver)

| iron | calcium | potassium valence | 3 | 2 | 1 electronegativity | 1.83 | 1 | 0.82 electron affinity | 15.7 kJ/mol (kilojoules per mole) | 2.37 kJ/mol (kilojoules per mole) | 48.4 kJ/mol (kilojoules per mole) first ionization energy | 762.5 kJ/mol (kilojoules per mole) | 589.8 kJ/mol (kilojoules per mole) | 418.8 kJ/mol (kilojoules per mole) ionization energies | 762.5 kJ/mol | 1561.9 kJ/mol | 2957 kJ/mol | 5290 kJ/mol | 7240 kJ/mol | 9560 kJ/mol | 12060 kJ/mol | 14580 kJ/mol | 22540 kJ/mol | 25290 kJ/mol | 28000 kJ/mol | 31920 kJ/mol | 34830 kJ/mol | 37840 kJ/mol | 44100 kJ/mol | 47206 kJ/mol | 122200 kJ/mol | 131000 kJ/mol | 140500 kJ/mol | 152600 kJ/mol | 163000 kJ/mol | 589.8 kJ/mol | 1145.4 kJ/mol | 4912.4 kJ/mol | 6491 kJ/mol | 8153 kJ/mol | 10496 kJ/mol | 12270 kJ/mol | 14206 kJ/mol | 18191 kJ/mol | 20385 kJ/mol | 57110 kJ/mol | 418.8 kJ/mol | 3052 kJ/mol | 4420 kJ/mol | 5877 kJ/mol | 7975 kJ/mol | 9590 kJ/mol | 11343 kJ/mol | 14944 kJ/mol | 16963.7 kJ/mol | 48610 kJ/mol

Reactivity

| iron | calcium | potassium term symbol | ^5D_4 | ^1S_0 | ^2S_(1/2) atomic radius | 140 pm | 180 pm | 220 pm covalent radius | 132 pm | 176 pm | 203 pm van der Waals radius | (unknown) | | 275 pm (electronic ground state properties)

| iron | calcium | potassium universe abundance | 0.11 mass% | 0.007 mass% | 3×10^-4 mass% solar abundance | 0.1 mass% | 0.007 mass% | 4×10^-4 mass% meteorite abundance | 22 mass% | 1.1 mass% | 0.07 mass% crust abundance | 6.3 mass% | 5 mass% | 1.5 mass% ocean abundance | 3×10^-7 mass% | 4.2×10^-4 mass% | 0.042 mass% human abundance | 0.006 mass% | 1.4 mass% | 0.2 mass% universe molar abundance | 0.002 mol% | 2×10^-4 mol% | 1×10^-5 mol% solar molar abundance | 0.003 mol% | 2×10^-4 mol% | 9.9×10^-6 mol% meteorite molar abundance | 7.8 mol% | 0.52 mol% | 0.037 mol% ocean molar abundance | 3.3×10^-8 mol% | 6.5×10^-5 mol% | 0.0066 mol% crust molar abundance | 2.3 mol% | 2.6 mol% | 0.78 mol% human molar abundance | 6.7×10^-4 mol% | 0.22 mol% | 0.032 mol%