rubidium vs calcium vs strontium

rubidium (chemical element) | calcium (chemical element) | strontium (chemical element)

Periodic table location

Images

| rubidium | calcium | strontium atomic symbol | Rb | Ca | Sr atomic number | 37 | 20 | 38 short electronic configuration | [Kr]5s^1 | [Ar]4s^2 | [Kr]5s^2 Aufbau diagram | 5s | 4s | 5s block | s | s | s group | 1 | 2 | 2 period | 5 | 4 | 5 atomic mass | 85.4678 u | 40.078 u | 87.62 u half-life | (stable) | (stable) | (stable)

| rubidium | calcium | strontium phase at STP | solid | solid | solid melting point | 39.31 °C | 842 °C | 777 °C boiling point | 688 °C | 1484 °C | 1382 °C critical temperature | 2093 K | | critical pressure | 16 MPa | | molar heat of fusion | 2.19 kJ/mol | 8.54 kJ/mol | 8 kJ/mol molar heat of vaporization | 72 kJ/mol | 155 kJ/mol | 137 kJ/mol specific heat at STP | 364 J/(kg K) | 631 J/(kg K) | 300 J/(kg K) (properties at standard conditions)

| rubidium | calcium | strontium density | 1.532 g/cm^3 | 1.55 g/cm^3 | 2.63 g/cm^3 liquid density | 1.46 g/cm^3 | 1.378 g/cm^3 | 2.375 g/cm^3 molar volume | 55.79 cm^3/mol | 25.86 cm^3/mol | 33.32 cm^3/mol Mohs hardness | 0.3 (between talc and gypsum) | 1.75 (between gypsum and talc) | 1.5 (between talc and gypsum) Brinell hardness | 0.216 MPa | 167 MPa | bulk modulus | 2.5 GPa | 17 GPa | shear modulus | | 7.4 GPa | 6.1 GPa Young's modulus | 2.4 GPa | 20 GPa | Poisson ratio | | 0.31 | 0.28 sound speed | 1300 m/s | 3810 m/s | thermal expansion | | 2.23×10^-5 K^(-1) | 2.25×10^-5 K^(-1) thermal conductivity | 58 W/(m K) | 200 W/(m K) | 35 W/(m K) (properties at standard conditions)

| rubidium | calcium | strontium electrical type | conductor | conductor | conductor resistivity | 1.2×10^-7 Ω m (ohm meters) | 3.4×10^-8 Ω m (ohm meters) | 1.3×10^-7 Ω m (ohm meters) electrical conductivity | 8.3×10^6 S/m (siemens per meter) | 2.9×10^7 S/m (siemens per meter) | 7.7×10^6 S/m (siemens per meter) magnetic type | paramagnetic | paramagnetic | paramagnetic volume magnetic susceptibility | 3.98×10^-6 | 2.139×10^-5 | 3.47×10^-6 mass magnetic susceptibility | 2.6×10^-9 m^3/kg (cubic meters per kilogram) | 1.38×10^-8 m^3/kg (cubic meters per kilogram) | 1.32×10^-9 m^3/kg (cubic meters per kilogram) molar magnetic susceptibility | 2.22×10^-10 m^3/mol (cubic meters per mole) | 5.531×10^-10 m^3/mol (cubic meters per mole) | 1.16×10^-10 m^3/mol (cubic meters per mole) work function | 2.26 eV (Polycrystalline) | 2.87 eV (Polycrystalline) | 2.59 eV (Polycrystalline) threshold frequency | 5.467×10^14 Hz (hertz) | 6.94×10^14 Hz (hertz) | 6.263×10^14 Hz (hertz) color | (silver) | (silver) | (silver)

| rubidium | calcium | strontium valence | 1 | 2 | 2 electronegativity | 0.82 | 1 | 0.95 electron affinity | 46.9 kJ/mol (kilojoules per mole) | 2.37 kJ/mol (kilojoules per mole) | 5.03 kJ/mol (kilojoules per mole) first ionization energy | 403 kJ/mol (kilojoules per mole) | 589.8 kJ/mol (kilojoules per mole) | 549.5 kJ/mol (kilojoules per mole) ionization energies | 403 kJ/mol | 2633 kJ/mol | 3860 kJ/mol | 5080 kJ/mol | 6850 kJ/mol | 8140 kJ/mol | 9570 kJ/mol | 13120 kJ/mol | 14500 kJ/mol | 26740 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 | 549.5 kJ/mol | 1064.2 kJ/mol | 4138 kJ/mol | 5500 kJ/mol | 6910 kJ/mol | 8760 kJ/mol | 10230 kJ/mol | 11800 kJ/mol | 15600 kJ/mol | 17100 kJ/mol

Reactivity

| rubidium | calcium | strontium term symbol | ^2S_(1/2) | ^1S_0 | ^1S_0 atomic radius | 235 pm | 180 pm | 200 pm covalent radius | 220 pm | 176 pm | 195 pm (electronic ground state properties)

| rubidium | calcium | strontium universe abundance | 1×10^-6 mass% | 0.007 mass% | 4×10^-6 mass% solar abundance | 3×10^-6 mass% | 0.007 mass% | 5×10^-6 mass% meteorite abundance | 3.2×10^-4 mass% | 1.1 mass% | 8.7×10^-4 mass% crust abundance | 0.006 mass% | 5 mass% | 0.036 mass% ocean abundance | 1.2×10^-5 mass% | 4.2×10^-4 mass% | 8.1×10^-4 mass% human abundance | 4.6×10^-4 mass% | 1.4 mass% | 4.6×10^-4 mass% universe molar abundance | 1×10^-8 mol% | 2×10^-4 mol% | 6×10^-8 mol% solar molar abundance | 4×10^-8 mol% | 2×10^-4 mol% | 7×10^-8 mol% meteorite molar abundance | 7.8×10^-5 mol% | 0.52 mol% | 2×10^-4 mol% ocean molar abundance | 8.7×10^-7 mol% | 6.5×10^-5 mol% | 5.7×10^-5 mol% crust molar abundance | 0.0014 mol% | 2.6 mol% | 0.0085 mol% human molar abundance | 3.4×10^-5 mol% | 0.22 mol% | 3.3×10^-5 mol%