Activity Definition and 193 Threads

Hi there, I was wondering if anyone could help me with this question ... "A device used in radiation therapy for cancer contains 0.50g of cobalt (60-Co-27). The half life of cobolt is 5.27 years. Determine the activity of the radioactive material." Working out: (To find the decay...

Homework Statement I am told to find the mass of Saturn using Kepler's Laws and the following information on Saturn's moons: Mimas r = 185.52 x 106 t = 8.14 x 104 Enceladus r = 238.02 x 106 t = 11.839 x 104 Tethys r = 294.66 x 106 t = 16.311 x 104 Dione r = 377.4 x 106...

We have been rockin and rollin here in the NW. http://www.sciencedaily.com/releases/2008/04/080413184801.htm

Dear All I am trying to do some Nuclear Fission based activity for my 12th grade students at school level. I shall be grateful if some one suggests such a low cast activity to perform at laboratory. Kind Regards Kosher.

Many of the chemical laws/concepts we deal with which relate some number to the 'quantity' of the reactants and/or products or the quantity of these substances among themselves, talk about 'activity'. For example, the law of mass action, or the Equilibrium constant. But I've seen that they...

[SOLVED] Activity series In my textbook, it list the acitivty series on a small table but the book does not explain why the series is the way it is. I am a bit confused. From the periodic chart Au looks more reactive than Pb. From what I understand the reactivity goes from left to right on...

Can anyone help me to understand the function of nitrogen in PWR. What I know about unstable N-16 is that it is used as an indication of power PWR. How fast does it achieve an equilibrium activity? ...

Hi guys, I've got to do a project for school on the investigation of the effect of pH on the enzyme amylase. I am abit lost right now only just started A levels. Can someone suggest how i would carry out this investigation? Equipment and method would be much appreciated! And the results need to...

The question: How many grams of Ba(IO3)2 can be dissolved in 700mL of a 0.100M KIO3 solution at 25C? use activity coefficients for this. (Ksp of Ba(IO3)2 =1.57E-9) my answer: I used this equation: Ksp = (concentration) * (activity coefficient) well i found out that my ionic strength...

Albert Einstein says that knowledge is a tree of which different specializations are its branches. Sri Krishna in Bhagwat Gita similarly, says that Knowledge is a tree upside down i.e., of which root is on top; and trunk, branches and leaves spread at bottom. If we all see the expansion of...

For humans, is it best to do nothing while eating? So that the digestive system can function with full vigour without resources directed to other activities during eating? From experience doing other physical activity is definitely not good but what about doing mental activities while eating...

Homework Statement This isn't acctually a problem but I really don't know what to do. I was doing a simple activity about Hooke's Law during class today where I have to set up a apparatus and measure the extension of spring when when we put differnt masses on it. I didn't do it properly so I...

I'll give three subjects to work with please tell me any descriptive attributes to them: Thinking: If you think with the knowledge you have now but expand on it does it help yourself? Also, how does learning have to do with this Learning: How do you know when your learning at your limit...

Who cares? It's for your own protection. Stop reading this thread, you spineless terrorist-supporters! Go away.

I was wondering what equations would be used to calculate the mass (in mg) of an isotope that gives an activity of 200 Ci.

Does anyone know how to calculate the specific activity [Ci/g] for radionuclides from halflife times? (using to calculate activity, sources are encapsulated and cannot be opened) Or, does anyone know of somewhere on the net the actual numerical values for each nuclide are? Neither my...

As I am playing chess, if I don't take a break after a few hours, my body temperature starts going up, is this normal?

Consider a cell in which you have driven the expression of a constitutively active GTPase Activating Protein (GAP) for CDC42, an important Rho-family GTPase. In these cells, CDC42's activity would most likely be: A.Downregulated because activating the GTPase function of CDC42 causes it to be...

fMRI data were collected from the brains of individuals either as they passively looked at geometric line drawings on a screen in front of them, or as they traced these drawings with their eyes. Data from the first task were subtracted from data from the second task. What area of the brain is...

"You are studying two radioisotopes, each of which contain the same number of undecayed atoms at the instant the activity of each is measured. Sample X has half life of 8 seconds, while sample Y has a half life of 1600 years. Which sample has the greatest activity? Explain." Im not sure. I...

http://www.fas.org/blog/secrecy/ What kind of hold does this man have on the current administration that he is allowed to carry out such outrageous acts. The man can classify his own actions and conduct at will. Yet he does not report that he has classified anything.

Is there a link between physical and mental activity? For instance, when I'm feeling tired, often if I exercise, if I don't do it to strenuosly, afterwards I'll feel much more awake and alert. I would assume that since your heart gets pounding faster and your body sort of wakes up, that your...

Sometimes it seems that my computer generates unwanted internet activity. I know this becuase I can see the activity light on my router blinking. This happens at irregular intervals. And when it happens, my internet connection stops working. I would either have to unplug my internet cable or...

We had a lab tonight involving enzymes. I am concerned about two of the results we got. Test tube #1 contained: 3 ml litmus cream + 3 ml distilled water + 3 ml lipase solution Test tube #2 contained: 3 ml litmus cream + 3 ml bile solution + 3 ml lipase solution Both were placed in a...

For next week's journal club I will be presenting "Neural Activity in Speech-Sensitive Auditory Cortex During Silence", Hunter et al. PNAS Jan 3, 2006 http://www.pubmedcentral.gov/articlerender.fcgi?tool=pubmed&pubmedid=16371474 Along with this paper, I would also like to present "Where the...

Either PF is having problems, or the NSA is on to me and are blocking my internet activity.

I know nothing about this science, but i was on mushrooms the other night and came up with an idea.. I've seen scans done on the discovery channel on the brain during certain thought processes. If you were to show a screen of red, compared to a screen of yellow to the subject, would...

hi, i am looking or a lab to measure the radioactive half-life of particles. i have looked through the internet but can't find anything i like. i have access to my college's physics/chemistry labretories and have equipment. so i just need procedures for a lab. can you Please suggest a link...

So I'm bored. Pick an activity or two that you like from the list. This is a public poll.

All right, before reading this, please understand that I am only in my second year of study in high school. Bear with me... When looking at the activity series or metals and comparing it to the electronegativity and ionization energies of the elements, I noticed something quite interesting...

Some rare footage from Lake Michigan: Six [simultaneous or nearly so] water spouts. http://woodtv.triton.net/video.woodtv.com/vid.player.php?video_id=1166 or http://woodtv.triton.net/video.woodtv.com/index.php?video_id=1166

Being a teenager and going through a Driver's Ed course, I'm constantly reminded that only time will sober you up after drinking, not a shower, not coffee, not a jog, nothing but time. This just seems stupid to me. Obviously jogging won't take you from hammered to sober, and I'm not going...

Is there any reason for order the activity series of ions in aqueous solutions? For example, why is Calcium higher than sodium?

Can someone explain what is an Activity Series? I looked at sites that is explaining it but I do not get it. Please try to make it simple as possible because I am really dumb. Thanks :smile:

http://www.mpg.de/english/illustrationsDocumentation/documentation/pressReleases/2004/pressRelease20041028/

A person is alive, animated, breathing, communicating, thinking, moving. There is brain activity - an energy which can monitored by a machine. Then suddenly their body is a cold lifeless shell and no brain activity can be found. In the terms of physics - what has happened? Where did that...

"No doubt": Human Activity Affecting Global Climate Change An interesting link that I had tucked away. http://globalchange.gov/ Here is one story from the link. http://globalchange.gov/

Greetings gentle readers, Ever heard of William Blum? He's a writer who has taken upon himself the task of showing the USA public exactly what their government does in their name. In aid of this, he lives near the Library of Congress, so as to spend his days in there gathering evidence -...

Hello All, I've always been curious about historical seismic activity prior to the 20th century. Then the advent of the last century until now, i have heard that seismic activity has increased dramatically. Then i got to conceptualizing how many underground nuclear test's have been...

Hi all, I am currently a college frosh taking cellular biology lab. In lab we did an experminet to measure how tempature effects enzyme activity. We put 1 mL of B-galactosidase (when a certain substrate is added to this enzyme, a yellow liquid (product) is formed). Then we use a Spec-20 to...

As with the Ghost Stories thread, I am posting a UFO news thread to which I or anyone else can add the latest UFO stories, events, or other news items. This is not intended to limit new threads; please feel free post one as you see fit. I just think this helps to reduce clutter on the board...

What is particle "spin", and does it have anything to do with radio activity? I keep hearing about the "spin" of sub-atomic particles like such-and-such particle has a spin of 1/2 or 1. I heard even some have a spin of 2. And it also seems that I have heard that some radioactive particles have...

optically active organic substances have the ability to rotate the plane of polarization of plane-polarized light. what i want to know is that how exactly do they rotate it?