HELIUM - பற்றிய அனைத்து டெக்னிக்கல் தகவல்கள் ! [00002]

 1. Symbol: He

2. Atomic Number: 2

3. Atomic Mass: 4.002602

4. Group: 18 (Noble Gases)

5. Period: 1

6. Block: s-block

7. Electron Configuration: 1s²

8. State at Room Temperature: Gas

9. Melting Point: -272.2°C (-457.9°F) at 2.5 MPa (helium does not solidify at standard pressure)

10. Boiling Point: -268.93°C (-452.07°F)

11. Density: 0.1786 g/L (at STP)

12. Isotopes: Helium-3 (³He) and Helium-4 (⁴He)

13. Most Abundant Isotope: Helium-4 (⁴He)

14. Phase at STP: Gas

15. Color: Colorless

16. Odor: Odorless

17. Taste: Tasteless

18. Flammability: Non-flammable

19. Critical Temperature: 5.2 K (-268.95°C, -452.11°F)

20. Critical Pressure: 0.227 MPa (2.25 atm)

21. Thermal Conductivity: 0.1513 W/(m·K) at 300 K

22. Speed of Sound in Helium: 965 m/s at 27°C (300 K)

23. Reactivity: Inert

24. Uses: Cryogenics, pressurizing and purging systems, gas chromatography, helium-neon lasers, arc welding, breathing mixtures for deep-sea diving

25. Discovery: Discovered in 1868 by Pierre Janssen and Norman Lockyer

26. Abundance in the Universe: Second most abundant element

27. Production Methods: Natural gas extraction, fractional distillation of liquefied air

28. Applications: Cooling superconducting magnets, filling balloons and airships, providing inert protective atmospheres for arc welding, and as a breathing gas in deep-sea diving