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

13

18

60

453

18

18

43

557

43

51

19

16

39

42

300

164

7933

45

14