Explain Kepler's laws

Kepler's three laws of planetary motion can be stated as follows: (1) All planets move about the Sun in elliptical orbits, having the Sun as one of the foci. (2) A radius vector joining any planet to the Sun sweeps out equal areas in equal lengths of time.

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Explanation:

Oxygen has 6 valence electrons. To fill up the valence shell, which (when in oxygen's row) has 8 electrons, an oxygen atom wants to gain 2 electrons. Since every electron has a single negative charge, the addition of two electrons results in an oxygen ion with a charge of −2

Oxygen is in group 6 of the periodic table meaning it has 6 electrons on its outer shell so when Oxygen atom gains two electrons it results in an Oxygen Ion with a charge of -2