Which does not describe the relationship between the nucleus and the electron cloud of an atom?
a. the electron cloud takes up much more space than the nucleus.
b. he masses of the nucleus and electron cloud are balanced.
c. the electrons move much faster than the particles in the nucleus.
d. the charges of the nucleus and electron cloud are balanced.

Choices 'a', 'c', and 'd' are true.

In choice 'b', I'm not sure what it means when it says that masses
are 'balanced'.  To me, masses are only balanced when they're on
a see-saw, or on opposite ends of a rope that goes over a pulley.

Maybe the statement means that the mass of the nucleus and the
mass of the electron cloud are equal.  This is way false.  It takes
more than 1,800 electrons to make the mass of ONE proton or
neutron, and the most complex atom in nature only has 92 electrons
in it.  So there's no way that the masses of the nucleus and the electrons
in one atom could ever be anywhere near equal.

On the galapagos islands charles studied finches

1.state2.trash3.the earth