23) Where did the elements heavier than hydrogen and helium come from?
24) Which planet, other than Earth, has visible water ice on it?
C) the Moon
25) According to our theory of solar system formation, why do we find some exceptions to the general rules and
patterns of the planets?
26) How does seafloor crust differ from continental crust?
27) Which two properties are most important in determining the surface temperature of a planet?
28) According to our theory of solar system formation, why do all the planets orbit the Sun in the same direction
and in nearly the same plane?
A) The original solar nebula happened to be disk
shaped by chance.
B) The laws of conservation of energy and conservation of angular momentum ensure that any rotating,
collapsing cloud will end up as a spinning disk.