hydrogen vs potassium vs rubidium vs cesium

hydrogen (chemical element) | potassium (chemical element) | rubidium (chemical element) | cesium (chemical element)

Periodic table location

Images

| atomic symbol | atomic number | short electronic configuration hydrogen | H | 1 | 1s^1 potassium | K | 19 | [Ar]4s^1 rubidium | Rb | 37 | [Kr]5s^1 cesium | Cs | 55 | [Xe]6s^1 | Aufbau diagram | block | group hydrogen | 1s | s | 1 potassium | 4s | s | 1 rubidium | 5s | s | 1 cesium | 6s | s | 1 | period | atomic mass | half-life hydrogen | 1 | 1.008 u | (stable) potassium | 4 | 39.0983 u | (stable) rubidium | 5 | 85.4678 u | (stable) cesium | 6 | 132.90545196 u | (stable)

phase at STP | all | gas | solid melting point | median | 33.88 °C | highest | 63.38 °C (potassium) | lowest | -259.14 °C (hydrogen) boiling point | median | 679 °C | highest | 759 °C (potassium) | lowest | -252.87 °C (hydrogen) | distribution | critical temperature | median | 2015 K | highest | 2223 K (potassium) | lowest | 32.97 K (hydrogen) | distribution | critical pressure | median | 13 MPa | highest | 16 MPa (potassium and rubidium) | lowest | 1.293 MPa (hydrogen) | distribution | molar heat of fusion | median | 2.14 kJ/mol | highest | 2.33 kJ/mol (potassium) | lowest | 0.558 kJ/mol (hydrogen) molar heat of vaporization | median | 69 kJ/mol | highest | 76.9 kJ/mol (potassium) | lowest | 0.452 kJ/mol (hydrogen) | distribution | specific heat at STP | median | 561 J/(kg K) | highest | 14300 J/(kg K) (hydrogen) | lowest | 242 J/(kg K) (cesium) (properties at standard conditions)

density | median | 1.19 g/cm^3 | highest | 1.879 g/cm^3 (cesium) | lowest | 8.99×10^-5 g/cm^3 (hydrogen) | distribution | liquid density | median | 1.46 g/cm^3 | highest | 1.843 g/cm^3 (cesium) | lowest | 0.828 g/cm^3 (potassium) | distribution | molar volume | median | 63.26 cm^3/mol | highest | 11200 cm^3/mol (hydrogen) | lowest | 45.7 cm^3/mol (potassium) Mohs hardness | median | 0.3 | highest | 0.4 (between talc and gypsum) (potassium and rubidium) | lowest | 0.2 (between talc and gypsum) (cesium) | distribution | Brinell hardness | all | 0.14 MPa | 0.216 MPa | 0.363 MPa bulk modulus | median | 2.5 GPa | highest | 3.1 GPa (potassium) | lowest | 1.6 GPa (cesium) | distribution | sound speed | median | 1300 m/s | highest | 2000 m/s (potassium) | lowest | 1270 m/s (hydrogen) thermal conductivity | median | 47 W/(m K) | highest | 100 W/(m K) (potassium) | lowest | 0.1805 W/(m K) (hydrogen) | distribution | (properties at standard conditions)

resistivity | median | 1.2×10^-7 Ω m (ohm meters) | highest | 2×10^-7 Ω m (ohm meters) (cesium) | lowest | 7×10^-8 Ω m (ohm meters) (potassium) | distribution | electrical conductivity | median | 8.3×10^6 S/m (siemens per meter) | highest | 1.4×10^7 S/m (siemens per meter) (potassium) | lowest | 5×10^6 S/m (siemens per meter) (cesium) | distribution | volume magnetic susceptibility | median | 4.62×10^-6 | highest | 5.74×10^-6 (potassium) | lowest | -2.23×10^-9 (hydrogen) | distribution | mass magnetic susceptibility | median | 2.7×10^-9 m^3/kg (cubic meters per kilogram) | highest | 6.7×10^-9 m^3/kg (cubic meters per kilogram) (potassium) | lowest | -2.48×10^-8 m^3/kg (cubic meters per kilogram) (hydrogen) molar magnetic susceptibility | median | 2.42×10^-10 m^3/mol (cubic meters per mole) | highest | 3.72×10^-10 m^3/mol (cubic meters per mole) (cesium) | lowest | -4.999×10^-11 m^3/mol (cubic meters per mole) (hydrogen) | distribution | work function | all | 1.95 eV | 2.26 eV | 2.29 eV

valence | median | 1 | highest | 1 (4 elements) | lowest | 1 (4 elements) electronegativity | median | 0.82 | highest | 2.2 (hydrogen) | lowest | 0.82 (3 elements) electron affinity | median | 47.6 kJ/mol (kilojoules per mole) | highest | 72.8 kJ/mol (kilojoules per mole) (hydrogen) | lowest | 45.5 kJ/mol (kilojoules per mole) (cesium) first ionization energy | median | 410.9 kJ/mol (kilojoules per mole) | highest | 1312 kJ/mol (kilojoules per mole) (hydrogen) | lowest | 375.7 kJ/mol (kilojoules per mole) (cesium)

term symbol | all | ^2S_(1/2) atomic radius | median | 228 pm | highest | 260 pm (cesium) | lowest | 25 pm (hydrogen) covalent radius | median | 212 pm | highest | 244 pm (cesium) | lowest | 31 pm (hydrogen) (electronic ground state properties)

universe abundance | median | 1.5×10^-4 mass% | highest | 75 mass% (hydrogen) | lowest | 8×10^-8 mass% (cesium) solar abundance | median | 2×10^-4 mass% | highest | 75 mass% (hydrogen) | lowest | 8×10^-7 mass% (cesium) meteorite abundance | median | 0.035 mass% | highest | 2.4 mass% (hydrogen) | lowest | 1.4×10^-5 mass% (cesium) crust abundance | median | 0.078 mass% | highest | 1.5 mass% (potassium) | lowest | 1.9×10^-4 mass% (cesium) ocean abundance | median | 0.021 mass% | highest | 11 mass% (hydrogen) | lowest | 5×10^-8 mass% (cesium) human abundance | median | 0.1 mass% | highest | 10 mass% (hydrogen) | lowest | 2×10^-6 mass% (cesium) universe molar abundance | median | 5×10^-6 mol% | highest | 93 mol% (hydrogen) | lowest | 1×10^-9 mol% (cesium) solar molar abundance | median | 5×10^-6 mol% | highest | 93 mol% (hydrogen) | lowest | 7×10^-9 mol% (cesium) meteorite molar abundance | median | 0.019 mol% | highest | 17 mol% (hydrogen) | lowest | 2×10^-6 mol% (cesium) ocean molar abundance | median | 0.0033 mol% | highest | 66 mol% (hydrogen) | lowest | 2.3×10^-9 mol% (cesium) crust molar abundance | median | 0.39 mol% | highest | 3.1 mol% (hydrogen) | lowest | 2.9×10^-5 mol% (cesium) human molar abundance | median | 0.016 mol% | highest | 62 mol% (hydrogen) | lowest | 1×10^-7 mol% (cesium)