Answer:

Explanation:
Given that:
The Half-life of
=
is less than that of 
Although we are not given any value about the present weight of
.
So, consider the present weight in the percentage of
to be y%
Then, the time elapsed to get the present weight of
= 
Therefore;

here;
= Number of radioactive atoms relating to the weight of y of 
Thus:

--- (1)
However, Suppose the time elapsed from the initial stage to arrive at the weight of the percentage of
to be = 
Then:
---- (2)
here;
= Number of radioactive atoms of
relating to 3.0 a/o weight
Now, equating equation (1) and (2) together, we have:

replacing the half-life of
=
( since
)
∴

The time elapsed signifies how long the isotopic abundance of 235U equal to 3.0 a/o
Thus, The time elapsed is 
As iron heats up, the arrangement of its atoms changes several times before it melts. ... Iron is magnetic at room temperature, and previous work predicted that iron's magnetism favors its open structure at low temperatures, but at 770 degrees Celsius iron loses its magnetism.
plz mark me as brainliest if this helped
It is called a watt and or wattage
Well all I know that animals take in oxygen and take out carbon dioxide and plants take in carbon dioxide and take out oxygen