Sr
Strontium
Alkaline EarthAtomic Number: 38 • Atomic Mass: 87.6200 u • Period: 5 • Group: 2
Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s²
Phase: Solid
Electronegativity: 0.95
Physical & Chemical Properties
Physical Properties
- •Soft, silvery-yellow, alkaline-earth metal
- •Highly reactive and quickly tarnishes in air
- •Slightly harder than lead but softer than calcium
- •Melting point of 1050 K (777°C)
- •Good conductor of heat and electricity
Melting Point
1050 K (776.85 °C, 1430.33 °F)
Boiling Point
1655 K (1381.85 °C, 2519.33 °F)
Density
2.64 g/cm³
Electronegativity
0.95 (Pauling scale)
Chemical Properties
- •Forms +2 oxidation state in nearly all compounds
- •Rapidly reacts with water to produce strontium hydroxide and hydrogen gas
- •Burns in air with bright red flame
- •Forms strong basic solutions in water
- •Compounds generally have low toxicity except for radioactive isotopes
Electron Configuration
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s²Electron configuration describes how electrons are distributed in atomic orbitals, showing how they are arranged in energy levels and subshells.