<span>Plants, Animals, and Disease between the Old and New Worlds.</span>
Answer:
8. The Chattahoochee River near Atlanta.
9. Much of the land the Union Pacific had to cover was plains/grassland/evergreen forests making the laying of track easier. The Central Pacific, however, had to cross the Sierra Nevada Mountains making the laying of the track very difficult.
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Answer: Marie Curie studied the radiation of all compounds containing the known radioactive elements, including uranium and thorium, which she later discovered was also radioactive. She also found out that:
- you can exactly measure the strength of the radiation from uranium;
- the intensity of the radiation is proportional to the amount of uranium or thorium in the compound - no matter what compound it is;
- the ability to emit radiation does not depend on the arrangement of the atoms in a molecule; it must be linked to the interior of the atom itself - a revolutionary discovery!
When she realized that some uranium and/or thorium compounds had stronger radiation than uranium, she made the following hypothesis: there must be an unknown element in the compound which had a stronger radiation than uranium or thorium. Her work aroused the interest of her husband, Pierre Curie, who stopped his own research on crystals and joined the "detective work" with his wife. And Marie was proven right
Fireworks and beer my guy
