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.
The answer is steamboats! The first steamboat came year 1807 and was invented by John Fitch:)
Pan Arabism is a political movement promoting the idea in which Arabs should unite in forming one country or a state. The idea was first done during 1800s in the later part and 1900s.If this stayed it would have led to greater unity for Arab and countries like Egypt and Syria could have stayed united which is the answer.
A the southwest isnt an area that is fully populated yet due to the land layout and the weather and lack of jobs
Ages because they indicate it the same way they do trees
hope this helped :)
