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.
25% of the civilians were killed in September 2015
Answer:
This is the thermosphere. It is the region of the atmosphere above the mesosphere and below the height at which the atmosphere ceases to have the properties of a continuous medium. The thermosphere is characterized throughout by an increase in temperature with height.
Explanation:
