Which best describes the nucleus of an atom?
a. it contains no mass.
b. it is the negatively charged part of the atom
c. it is made of neutrons and electrons.
d. it is the most massive part of the atom.

D. It is the most massive part of the atom.

Explanation:

As you know, an atom is formed by the electrosphere (where the electrons are) and the nucleus (where the neutrons and protons are).

The nucleus is a very small region in the atom and although it occupies less space than the electrosphere, it contains practically the entire atomic mass, for this reason it is the densest region of the atom. This is because the entire mass of an atom corresponds to the sum of all its protons and the protons are in the nucleus.

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

hope this .. .

c: warm water flows from the western tropical pacific toward south america. that should be the right answer! hope it .