A sample of radioactive isotape contains 320 million atoms of the isotape. A how many atoms are present after
a) one half life
b) five halve lives
half life question please help?
2013-01-19 3:07 pm
回答 (4)
2013-01-19 3:12 pm
✔ 最佳答案
Nf=No(1/2)^#of half lives
2013-01-19 11:13 pm
a)
After one half-life,
There remains 320m * 1/2 = 160m atoms.
b)
After five half-lives,
There remains 320m * (1/2)^5 = 10m atoms.
After one half-life,
There remains 320m * 1/2 = 160m atoms.
b)
After five half-lives,
There remains 320m * (1/2)^5 = 10m atoms.
2013-01-19 11:12 pm
after one half life no. of radio active atoms=half of original ie 0.5*320=160
after 5 haf lives=320*(0.5)^5=320/32=10
after 5 haf lives=320*(0.5)^5=320/32=10
2013-01-19 11:09 pm
a half life is the time it takes for half of the atoms to be "used" so half fthe first one for a
the for the second one you need to half the original five times to find five half life's
the for the second one you need to half the original five times to find five half life's
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