Question

Not math....but I'd love the help :)
Please explain your answer and how you got it as simply as possible...haha :)
Two scientists are experimenting with pure samples of isotope X, a highly radioactive substance. The first scientist has a sample with a mass of 20 grams. He measures a half-life of 232 seconds. The second scientist has a sample of the same substance with a mass of 80 grams. What is the half-life that she is most likely to measure?
A. 58 seconds
B. 232 seconds
C. 464 seconds
D. 928 seconds

Answer 1

It's still math. :P
But it's chemistry math, and that stuff scares me.

Answer 2

half life is the same for the same radioactive substance. seems to me you don't really understand what half life means

Answer 3

can you guess the answer now? :P

Answer 4

No I only know how to do these ones...and...to tell you the truth this subject is fairly new to me

Suppose you have 60 grams of a radioactive isotope. The isotopes half life is 15 minutes. how much of the material will you have after 30 minutes?
At 30 minutes, two hlf lives will have passed. You will have 25% of the original material, or 60(.25) = 15 grams.

i may seem stupid sorry.
But would you mind explaining? :)

Answer 5

You need radioactivity explained? Sure:

Radioactive + spider + bite = radioactive human = spiderman fan who is dead.

Answer 6

HAHAHAHA
You are soooooooooooo not helping >:P
LAWLS

Answer 7

http://math.ucsd.edu/~wgarner/math4c/textbook/chapter4/expgrowthdecay.htm

A more serious note. Hopefully that helps? I'm sorry, but chemistry is not my 'thing'.

Answer 8

creepy, do you understand radioactivity?

Answer 9

No, not really. >.<

Answer 10

Can you explain? :)

Answer 11

okay. radioactivity basically means that some heavy elements, such as U-235, U-238 and Plutonium spontaneously decay. That is, they spontaneously emit radiation.
we know that mass is basically energy from einstein's famous equation
e= mc^2
so, when these heavy isotopes emit radiation, what actually happens is that their mass is converted to energy and emitted as radiation. That is why radiation is so dangerous. It is basically energy.
so, when their mass is converted to energy, there is less and less of the elemtn left.
half life describes the rate at which the isotopes lose their mass and convert them to energy.
so if you say 60 grams of isotope has a half life of 15 minutes, it means that in 15 minutes, half of the isotope is emitted as radiation. that is, 30 grams became energy in 15 minutes. in another 15 minutes, half of the remaining 30 grams becomes energy.
so after half an hour, you are left with 15 grams of isotope left which has not yet become energy.

Answer 12

this is a very basic and descriptive explanation. if you want real explanation, you should read it up online on wikipedia or some other place.