Summary on law of conservation plz

One specific historical event or development during the period 1786-1861?

How did the battle of okinawa affect president truman’s decision to use the atomic bomb against japan? it showed that japan was close to surrendering. it showed that the us could not win the war without it. it showed that japan was willing to fight to the end. it showed the us could easily defeat japan.

Brainliestttme : ) what demographic changes occurred after world war ii?