Answer:
space or any other extraterrtial beings
Explanation:
Answer:
Radioactive isotopes are unstable and will decay. ... The isotopes will decay into a stable isotope over time. Scientists can tell how old the rock was from looking at the radioactive isotope's half-life, which tells them how long it would take for there to be half the radioactive isotope and half the stable isotope.
Answer:
Arithmetic Density
Explanation:
it is the total number of people divided by the total land area and this is just talking about population density not the amount of arable land (physiological density) or comparing the number of farmers to the area of arable land (agricultural density)