To fill up all of the valence electrons we must have 8 electrons total to have an ionic bond. In this case Lithium is in group 1 and so only has 1 valence electron and so it can bond with elements from group 17, since 7 + 1 = 8. However, this unknown element did bond with beryllium, and beryllium is in group 2 so it must bond with an atom that has 6 valence electrons. The elements that have 6 valence electrons are in group 16 not group 2. So the result does not support her conclusion.
Light is a <span>wave of vibrating electric and magnetic energy.</span>
Answers : part A => vs= square root (Gmp/a). Part B => Energy of satellite = - G(mp) (ms) / 2a.