I'm not sure what your question is. But, the half life is the amount of time required for half the material to decay. For U238 this is 4.5 billion years, whilst for Fr-223 (Francium) its about 22 minutes. To calculate the time for something to decay you need to use the equation:
Mass (after time t) = Mass (initial) * (0.5)^(time/half life)
Hope this helps
Hello,
Here is your answer:
The proper answer for this question is that they "get absorbed by the ozone layer".
If you need anymore help feel free to ask me!
Hope this helps!
Answer:
kinetic energy=1/2mv^2.
which is 4320000=1/2×m×23^2.
which is 4320000=1/2×m×529.
4320000=264.5m.
m=4320000/264.5.
m=16332.70~16333g
Well, the thing is: we don't really know, as we don't even know how many species there are on earth.
If we take a look at the estimates of <span>World Wide Fund for Nature, an organization that works toward combating species extinction, their estimates vary from 200 to 100 000 - but a probable number is 20 000 (d). </span>
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