Explanation:
HCL you can do it yourself .try again
The shape of the molecule will determine the direction of each of the individual bond dipoles, and thus, will always play a role in determining the polarity of the molecule as a whole.
Answer:
They can be dated using radioactive carbon. But for rocks older than 50 thousand years they look for layers of igneous rock or volcanic ash above and Bellow the layer of rock/fossil.