Earth’s surface did not solidify during the first half billion years after its formation because A. the planet spun too fast.
B it was completely covered by water.
C: clouds of dust and gas made the air too dense.
D: meteorite bombardment made Earth’s surface hot and liquefied.

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?  

Mg-26 and mg-24 are pair of isotopes. isotopes are defined as atoms of the same element having same atomic number but different mass number. i hope that was .

We can't until we know what we are working with or on

The answer is c.  h+  and oh−  react to form water (h2o). i just took the test and i got it right. hope this !