Article Detail Which is the lightest gas ? Answer: Hydrogen Similar Questions : 1. Which is the largest Zoo in India ? Answer: Zoological Gardens, Alipur, Kolkata 2. Which is the biggest museum in the world ? Answer: British Museum, London 3. Which is the largest gulf ? Answer: Gulf of Mexico 4. Which is Longest road tunnel in the World ? Answer: Lærdal Tunnel (Norway - 24.51 kilometre) 5. Which is largest Delta of India ? Answer: Sundarban (W. Bengal) 6. Which is Longest national highway of India ? Answer: NH-7 ( Varanasi to Kanyakumari - 2,369 km) 7. Which is the state largest by area in India ? Answer: Rajasthan Read more from - Longest and Largest