Answer:Minerals form when rocks are heated enough that atoms of different elements can move around and join into different molecules. Minerals are deposited from salty water solutions on Earth's surface and underground
Explanation:
Answer:
The electrons are lost from the valence shell (outermost electron shell) of the atom.
Explanation:
This is able to be inferred not only because valence electrons being lost first is a trend but also because the atom in question has actually 3 valence electrons (13-2-8 = 3).
Mass of X₂O₇ = 54,9g
2x + 33,6g = 54,9g
2x = 54,9g - 33,6g
2x = 21,3g | :2
x = 10,65g/mol