Chemistry 5-6-09 Half-Life Problems
So how did you like half-life problems? Think them through – you can do it!! Here’s the vodcast from Wednesday. NO AUDIO! Let it load all the way, then fast forward to where I write out the problems, if you need help. Sorry about that – I think we’ve got us some gremlins! Or maybe just a chemistry teacher who can’t figure out the correct settings for the mic. Myself, I’m voting gremlins!
May 8th, 2009 at 6:04 AM
what is half life?
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Mary Gates Talbot Reply:
May 8th, 2009 at 10:21 AM
half life is the amount of time that it takes for half of the atoms to decay
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May 8th, 2009 at 6:22 AM
what are the steps we are suppose to follow when working a time problem?
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May 8th, 2009 at 6:43 AM
Jordan,
1: You would find the fraction left ( of the atoms) by putting the amount you have left over the amount you began with.
2: Then you would figure out how many half lives it took to get that fraction left over. 3: You times that answer by how ever long one half life is.
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May 8th, 2009 at 7:19 AM
What formula do we use to solve the mass remaining problems?
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May 8th, 2009 at 7:56 AM
how many types of half-life problems are there and what are the called?
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May 8th, 2009 at 9:28 AM
katherine:
a half life is the time it take for half of an atom to decay.
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May 8th, 2009 at 9:29 AM
Preston: There are 2 kinds of half life problems Mass and Time.
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May 8th, 2009 at 9:34 AM
how do you find the fraction left when working a time problem.
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May 8th, 2009 at 10:08 AM
what is the mass formula for solving a half-life problem?
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May 8th, 2009 at 10:22 AM
do they use half life problems like this in carbon dating?
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May 8th, 2009 at 11:59 AM
how do you begin a mass problem
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May 8th, 2009 at 1:18 PM
preston,there are two kinds of half-life problems.
i think they are called mass and time.
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May 8th, 2009 at 2:19 PM
Ash-
To solve a mass problem, you must always start with finding the fraction of time remaining.
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May 8th, 2009 at 4:22 PM
how can radioactivity hurt a human?
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May 8th, 2009 at 4:57 PM
emma: radiation can mess with a persons genes and cause gene mutations.
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May 8th, 2009 at 5:44 PM
why is knowing the half life of an element important?
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May 8th, 2009 at 7:22 PM
it shows there number of years
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May 8th, 2009 at 9:50 PM
what is the formula to find the mass remaining after a half life of decay
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May 8th, 2009 at 10:00 PM
so are there only half life problems or are there full life problems too?
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Borr Reply:
May 9th, 2009 at 2:48 AM
Cody i think there is only half life problems
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May 11th, 2009 at 6:54 PM
how do you find time remaining?
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May 11th, 2009 at 10:33 PM
Beth Ann-
It’s important to know the half life because that’s how we see how long it take to decay. And the quicker it decays the more dangerous it is. Like uranium and plutonium. But if it has a long half life like in years then it is not as dangerous.
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May 11th, 2009 at 11:24 PM
audrey-
to find the time remaining, you have to find the fraction of mass remaining. once you have the fraction, you convert it to # of half-lives and then multiply the # of half-lives by the time for one half-life…i think that’s right anyways. haha. :]
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