<span>C.)The average rate at which a mountain range rises each year is used to estimate how long ago the range began to rise.
Since geological time and movement takes place over a huge amount of time, most geologist measure the geological time by taking the average rate of almost all the sample and compare. </span>
Doppler effect and redshift as the light coming from stars from the distance can be shifted in the same way as a pitch of sound does
Isotopes are variants of a particular chemical element which differ in neutron number (neutral particle)and all isotopes of a given element have the same number of protons (positive particle) in each atom.So isotope B of the sodium will have 11 protons, 11 electrons but it may have a wide range in its number of neutrons.
b is the correct answer. hope this helps
Permian-Triassic extinction