The half-life of polonium-218 is 3 min. if you start with 16 mg, how long will it be before only 1.0 mg remains?

i think it was because of how protected egyptian civilization was was which allowed them to evolve without much outside influence.

when world war i broke out across europe in 1914, president woodrow wilson proclaimed the united states would remain neutral, and many americans supported this policy of nonintervention. however, public opinion about neutrality started to change after the sinking of the british ocean liner lusitania by a german u-boat in 1915; almost 2,000 people perished, including 128 americans. along with news of the zimmerman telegram threatening an alliance between germany and mexico, wilson asked congress for a declaration of war against germany. the u.s. officially entered the conflict on april 6, 1917.