Answer:
about 5 billion years ago
Explanation:
Our solar system formed about 5 billion years a go from a dense cloud of interstellar gas and dust.
<span>Valence is defined as number of electrons that are present in the outermost orbital. Oxygen is in the 16th column of the periodic table and the total number of valance electrons is determined by units place digit of the column position which is 6 for oxygen. The outermost orbital is the high energy level and there are two in that orbit. So the valance is +2.</span>
aquifers yaaaaaaaay water from underground usually comes from aquifers
