What is the most common element (by mass) forming the planet Earth?
carbon
oxygen
iron
silicon
Iron is most abundant in the Earth's outer and inner core, and it is the fourth most common element in the Earth's crust.
reach: rather globalastronomychemistryEarthelementsgeologytechnology
Answers by country
carbon
oxygen
iron
silicon
answers

16

18

60

450

18

43

16

537

43

51

16

39

18

42

7782

160

42

268

14

13