Which gas is most abundant in Earth’s atmosphere? By Rabia Anum 🌐 Source Science & Technology Archive ✅ Fact Checked 📊 Difficulty Easy 📅 Last Updated 13 Aug 2026 A. Oxygen B. CO2 C. Nitrogen D. Argon Check Answer 💡 Explanation: Nitrogen makes up approximately 78% of the Earth's atmosphere. 📚 Topics: Earth Science Science 🎯 Exams: CSS GEN NTS PMS