<span>Africa was more south and west and South America was more south and east of their current positions. I would say this would be because because South America and Africa used to be together in Gondwanaland millions of years ago and then apparently drifted apart as Wegener thought and then with the advent of plate tectonics it became apparent that the mid-Atlantic ridge runs between them and due to spreading along it Africa and S America got separated.</span>
What did Dalton's atomic theory contribute to science?
Dalton's atomic theory proposed that all matter was composed of atoms, indivisible and indestructible building blocks. While all atoms of an element were identical, different elements had atoms of differing size and mass.
Answer:
The atoms share some of their outer electrons so that each atom has a stable noble gas arrangement.
Explanation:
Mass of X₂O₇ = 54,9g
2x + 33,6g = 54,9g
2x = 54,9g - 33,6g
2x = 21,3g | :2
x = 10,65g/mol
