Documents Grade 7 Science. 3 very long Eons: Hadean, Archean and Proterozoic; Covers 87% of earth’s...

Slide 1 Grade 7 Science Slide 2  3 very long Eons:  Hadean,  Archean and  Proterozoic;  Covers 87% of earth’s history;  Formation of earth, volcanic activity;…