Use the Harvard Classification Scheme (shown in the table above) to answer the following quesiton: The Sun contains spectral lines from neutral sodium and calcium as well as ionized calcium, magnesium and iron. Of the choices below, which could be the surface temperature of the Sun

7is b8 is d9 is c10 is a11 is d

Okay well gravitational energy is matter forced by gravity making energy though the kinetic energy then the electric energy produces electricity from the kinetic energy and the kinetic energy gets its energy from the gravitational energy. was that the answer you wanted or something else?  

While unproven, it uses facts to support part of a conclusion. it is still factual and has predictive power, however.