Q. Which among the following is the most abundant element by mass in Earth’s Crust ?
Answer: Oxygen
Notes: Oxygen is the third most abundant element in the universe by mass after hydrogen and helium and the most abundant element by mass in the Earth's crust. In Earth's crust, Oxygen is 46.6% by mass, followed by Silicon 27.7% and Aluminium 8.1%.

This question is part of 40000+ General Studies MCQ Series Course on GKToday Android app. Question Number: 16 in Geology Geological Time Earths Internal Structure in above course in App.