Positron emission by fluorine -18, which is used in PET scans to study brain functions produces which new element?
Mass # = Atomic # = Symbol =
Asked by Delila Wedderburn 2 years ago.
Fluorine-18 Mass number .... 18 Atomic number .... 9 Symbol ................. F-18, or 9F18, or .............................. 18 .................................. F ................................ 9 Fluorine-18 decays by positron (anti-electron) emission to make oxygen- 18. An anti-electron is antimatter and has the same properties as an electron except charge. A positron has a relative charge of +1, rather than the -1 of an electron. Answered by Jean Schapp 2 years ago.
please help! i need to know where fluorine-18 is found and it's natural abundance?
Asked by Hsiu Price 2 years ago.
Natural fluorine is F-19 which has an abundance of 100% so F-18 is not found in nature. It is produced in cyclotrons and accelerators to be used in medicine as a positron emitter in positron emission tomography. Answered by Paulita Conneely 2 years ago.
Chemistry question...help me?
Q:The only stable isotopes of fluorine is fluorine-19. Predict possible modes of decay for fluorine-21, fluorine-18 and fluorine-17. please tell me step by step...i really dont get this...thanks!~
Asked by Gregoria Gammel 2 years ago.
Naturally occuring stable isotope of fluorine (at.no: 9 and mass no: 19) has 9 protons and 10 neutrons. Now let's see the atomic compositions of the radioisotopes: F-21 : 9 proton - 12 neutron F-18 : 9 proton - 9 neutron F-17 : 9 proton - 8 neutron F-21 has more neutron, F-17 and F-18 have less neutron compared to the stable isotope. These differences in the number of neutrons determine their modes of decay. F-21 should decrease its number of neutrons to gain stability. This is achieved by beta emission. Because in beta emission, one of the neutrons in the nucleus is converted to proton and electron: (0 and 1) n --------> (1 and 1) p + (-1 and 0) e the first figure in parenthesis represents the charge and the second figure represents the mass in nuclear symbols) proton remains in the nucleus and increases the atomic number by 1 unit and electron is thrown as beta particle. The nuclear reaction is; (9 and 21) F ---------> (10 and 21) Ne + (-1 and 0) e F-17 and F-18 should increase their number of neutrons to gain stability. This is achieved by positron emission or electron capture. Because in positron emission, one of the protons in the nucleus is converted to neutron and positron: (1 and 1) p --------> (0 and 1) n + (+1 and 0) e On the other hand in electron capture, one electron from K-shell is attracted by the nucleus where it combines with a proton to form a neutron: (-1 and 0) e + (1 and 1) p ----------> (0 and 1) n In both types of decays, the mass number does not change, but the atomic number decreases by 1 unit. Electron capture: (9 and 17) F + (-1 and 0) e ---------> (8 and 17) O (9 and 18) F + (-1 and 0) e ---------> (8 and 18) O Positron emission: (9 and 17) F ---------> (8 and 17) O + (+1 and 0) e (9 and 18) F ---------> (8 and 18) O + (+1 and 0) e Answered by Verna Fernholz 2 years ago.
Fluorine 18 Decay Answered by Lawrence Tashiro 2 years ago.
Favourite element and why?
For my chemistry homework i have to say what my favourite element of the periodic table is and why. Could you say what yours is, why and a few facts about it. Please it would really help me. Thanks.
Asked by Leah Meiss 2 years ago.
Fluorine is by far the most interesting element. 1. the most electronegative 2. the second smallest after H 3. the most reactive non-metal Fluorine is highly important in organic chemistry, pharmaceuticals, medicine, and drugs. The carbon fluorine is one of the strongest bonds between carbon and any other atom. In medicine, Fluorine's radioactive isotope F-18 is used to do PET Scans which doctors used to trace drugs administered into patients to come out with a diagnosis or find out what areas of the human body are drugs affecting. For example, if you are treating a cancer patient with an anti-cancer drug you can tag the drug with an F-18 isotope and then trace it (like a GPS system follows your car) to see if the drug is going where it is supposed to go and doing its job. A lot of drugs made from pharmaceuticals contain either contain a F atom, a CF3 group, or a several F atoms placed specifically in certain locations. The reason for this is because the drugs are more effective. They get to where they need to get much faster. When you take a pill, the acids in your stomach dissolve the pill and then the drug gets into your blood but before it does this it needs to pass through the layers of fat and this becomes the hardest part of all. So by adding F atoms you make the drug a bit more slippery and it gets to where it needs to get to much faster. It's like a newspaper boy delivering newspapers to their homes. If he uses a bicycle it takes a long time but if he uses a car or a much faster method of transportation then his job will be much easier. Answered by Toby Lucien 2 years ago.
I like all of them when Tom Lehrer sings about them. Go to the youtube reference below. Answered by Wilfredo Firestone 2 years ago.
i like carbon. diamonds are cool. graphite is cool. both have carbon, in a similar way, yet one is really tough and the other not so. Answered by Elois Pascale 2 years ago.
You should decide on your own. Answered by Felisa Clearman 2 years ago.
Chemistry problem....Need HELP! (Effects and Applications of Radioactivity)?
PET studies require fluorine-18, which is produced in a cyclotron and decays with a half-life of 1.83 hours. Assuming that the F-18 can be transported at 60.0 miles/hour, how close must the hospital be to the cyclotron if 64% of the F-18 produced is to make it to the hospital? Ans. ? mi
Asked by Mercy Grabhorn 2 years ago.
The decay process has an exponential decay, which in this case means that every 1.83 hours, half the F-18 decays. Exponential decay can be described by the following equation (see source for better formatted version): Nt = No x (1/2)^(t/t½) (Where Nt is the amount of F-18 remaining after time t, t½ is the half life and No is the original amount of F-18) This equation can be rearranged to get an equivalent equation that is easier to calculate: t½ = t / log2(No/Nt) If we start with 100% F-18: 1.83 = t / log2(100/64) = t / log2(1.5625) So: 1.83 = t / 0.644 Therefore t = 1.18 At 60 mph, you travel 70.8 miles in 1.18 hours. Answered by Maris Ginter 2 years ago.
the biggest result's that Imperial Japan signed the unconditional renounce and WWII complete in the Pacific without further causalities. a chronic US invasion and land combat could reason many greater causalities and suffering. The radioactivity is subsided by now and there are little if any outcomes on life. Hiroshima and Nagasaki could be a warning to mankind that aggression brings misery. Answered by Luanne Hemrick 2 years ago.
Half-life problem help please?
At 8:15 a.m., a PET scan patient was injected with a compound containing fluorine-18. Assuming that none of the compound is excreted, what fraction of the 18F remains in the patients body at noon? Thank you!
Asked by Richie Christmas 2 years ago.
You need the half life. I assume you were given it, if no, you'll need to look it up. How much time has elapsed between 8:15 am and noon? How many half lives is that? fraction remaining = 0.5^n where n is the number of half lives. Answered by Mandy Covarrubia 2 years ago.
When 5.49 g of platinum reacts with an excess of fluorine, 7.63 g of platinum(-) fluoride forms?
A. what is the mass of fluorine in the compound?B. calculate the number of moles of platinum that react.C. calculate the number of mole of fluorine that react.D. what is the ratio of moles of F to mole pt that react? what is the empirical formula of platinum() fluoride, ptF? give the correct name for the...
Asked by Katherina Garelik 2 years ago.
A. what is the mass of fluorine in the compound? B. calculate the number of moles of platinum that react. C. calculate the number of mole of fluorine that react. D. what is the ratio of moles of F to mole pt that react? what is the empirical formula of platinum() fluoride, ptF? give the correct name for the compound. Please help answer this questions thanks. Answered by Carlena Kanta 2 years ago.
A. 7.63 g - 5.49 g = 2.14 g F B. (5.49 g Pt) / (195.0849 g Pt/mol) = 0.0281 mol Pt C. (2.14 g F) / (18.9984 g F/mol) = 0.113 mol F D. (0.113 mol) / (0.0281 mol) = 4.02 = 4 PtF4 platinum tetrafluoride Answered by Cleveland Rowett 2 years ago.