Answer:
It was the last element first discovered in nature, rather than by synthesis. Outside the laboratory, francium is extremely rare, with trace amounts found in uranium and thorium ores, where the isotope francium-223 continually forms and decays
Ionic bonding is a type of chemical bonding that involves the electrostatic attraction between oppositely charged ions, or between two atoms with sharply different electronegativities, and is the primary interaction occurring in ionic compounds
Answer:
6.70 grams of krypton-81 was present when the ice first formed
Explanation:
Let use the below formula to find the amount of sample

where

here
t = 458,000 years
= 229,000
= \
n =
= 2.000
Now substituting the values



