Explain in you own words, why molecules sometimes attain three-dimensional shapes rather than just being flat.

The Valence Shell Electron Pair Repulsion Theory states that bonding pairs and lone pairs of electrons in valence level of an atom repel one another. You lose and gain electrons.

200 million years.
the exact answer is  226 million years.
the planets in our solar system orbit around the sun. one orbit of the earth takes one year. meanwhile, our entire solar system orbits the center of the milky way galaxy. our sun and solar system move at about 800 thousand kilometers an hour – that’s about 500 thousand miles an hour – in this huge orbit. so in 90 seconds, for example, we all move some 20,000 kilometers – or 12,500 miles – in orbit around the galaxy’s center.