Answer:
Most radioactive materials decay and they mostly have a decay rate. The time it takes for half of a radioactive material to decay is called half life.
The 7 minute significance of half-life simply points to the total time it takes after which half of the radioactive material would have completely decayed,
Slow cooling of hot magma leads to the formation of large crystals
To measure the kinetic engery from the inside and outside of something to be able to tell how hot or coll something is.. without touching it also
