Radium is found in natural deposits and has a half life of about 1.620 E3 years. The age of the Earth is 4.5E9
601803
not much\nsomething else decays into radium, or is recombinant
26543
There is 3 types of naturaly occuring isotopes for Uranium\n\nuranium-234 has a half life of 244 thousand years\nuranium-235 has a half life of 704 million years\nuranium-238 has a half life of 4.5 billion years\n\nIf you meant Fermium-253 then it is 3 days (Fermium is made by bombarding plutonium with neutrons)
1109602
Scientific evidence suggests that the Earth is actually around 4 billion years old.  We have shown that many fossils are more than 6000 years old by using carbon-testing and other accurate tests.  We have used geological evidence as well.  Thus, that prediction of the Bible is probably incorrect, although that doesn't mean that you should disregard the Bible.
91365
Ignore the abusive idiot above. He has no idea what he is talking about.\n\n\nThere are lots of different radioactive elements. Some are dangerous but the vast majority are harmless. \n\nYour body and everybody else's is already full of radiocative elements. You are loaded with isotopes like 13Carbon., tritium, 44Calcium and so on. Every living thing that has ever existed on Earth has been losded with those radicoative elements. We've evolved with them from the beginning and as a result they are quite harmles to us in normal doses.\n\nA few unnatural radioactive isotopes are harmful in small doses, and some natural isotopes are dangerous if they are concentrated in the body. But the general answer is that radiocative elements are quite harmless.
288544
your first question is somewhat political so i am not answering that but your second question ,that's physics so i will answer that.\nthe radioactive elements have this special property called half-life.\ni will use this eg to explain it.\nthink that you have in your hand 1kg of uranium(dont show that to bush)and assuming its half-life to be around  thousand years ,you will find that after 1000years the uranium in your hand will have decayed and only 0.5kg of the total will be left.and it keeps on like that.so it kinda never ends.Hope you understood.
851623
Earth's age is based on several things:\n\n1) dating meteorites. When we find a meteorite from this solar system that has a similar composition to earth, you get many young ages, but the oldest and most common date to 4.6 Ga (billion years).\n\n2) isotope trends. When you look at certain radiogenic isotope ratios that change with time, like Rb/Sr or U/Pb, you find that many rocks with differnt ratios of many ages form a line, and the line traces back to an origin of 4.6 Ga as well.\n\nThe oldest life is 3 1/2 Ga, the oldest rock is about 4 Ga, and the oldest date ever found is on the highly durable mineral Zircon from Australia, it's date is 4.2 Ga. So, there is no direct method, it is based on inferences. However, many different inferences lead to the same number 4.559 Ga (to be specific).\n\nYou would have to throw out everything we know and love about Geology to accept a young earth view. When you look at the Grand Canyon, how can you say that only took 6000 years to form?
382215
The Earth is assumed to be about 4.6 billion years old, and unlike what everyone else said, it's not based solely on anything contained on Earth, including carbon dating. The oldest solid material found on Earth is about 4.1 billion years.\n\nThe guess -- and that's all it is, a guess -- is based on the rate of radiological decay of material on Earth and in meteorites found on Earth and around the solar system.\n\nIf you assume that the entire universe is formed from a common pool of matter (the essence of the Big Bang theory is that all material in the universe came from a single, supercondensed source that exploded); if you assume that therefore, all the matter in the universe has been equally distributed in all directions; if you assume that the rates of decay in all radiological material in the universe are consistent regardless of time, their position in the universe, etc.; then you can derive, by comparing the same kind of radiological material from celestial bodies that were not formed in our solar system, bodies that were part of our solar system when it formed, and that material now on Earth, the age that the Earth must be at the time it began to take solid form.\n\nThe paticular materials used to get that age is Lead-206 / Lead-207, which are the products of decay in Uranium-238.\n\nThis is further supported by temperature measurements of the universe and the evidence of background radiation from the timing of the Big Bang, which is assumed to have occurred about 15 billion years ago; given the rate of expansion of the universe visible to us, and the rate of change in both the speed of that expansion, the temperature of the universe and the density of space, we can verify the assumptions of the Earth's age to be within the estimation of a "young Earth" of 4.6 billion years old.\n\nAlso, to the person who said "The Bible": If you derive the history of the Earth from the Bible, as countless theological scholars have done through extensive research, it's about 6,000 years old; no scholarly Biblical research places the age of Earth at more than 10,000 years old.\n\nIf you want to believe that, in the face of overwhelming evidence to the contrary, that's fine. But you should at least agree with your evidence before citing it.
496873
Sorry this is so long, but I have to first fix some misinformation given in other people's answers.  Specifically, carbon-14 (a.k.a. C14, carbon dating, or radiocarbon dating) is useful for dating a lot of things, but *not* fossils!  Instead, other forms of radiometric dating are used for fossils.  \n\nThe 'half-life' is a measure of how fast the process of radioactive decay causes one type of atom to decay into another type.  For example carbon-14 (C14) decays into nitrogen-14 (N14) with a half-life of 5,730 years.  This means that if you have a bone with 1 gram of C14, then after 5,730 years, 0.5 grams will have decayed to N14, leaving 0.5 grams of C14.  After another 5,730 years only 0.25 grams would remain.  And so on.\n\nNow, 5,730 years is not very long in geologic terms.  This means that after 50,000 years or so, the amount of C14 left is so small that it is practically unmeasurable.  It's for this reason that C14 dating is not much good for fossil dating, as most fossils are *much* older than 50,000 years.\n\n[Aside:  There's another reason carbon-14 dating is not useful for fossils.  It's only useful for dating once-living matter (bones, wood, teeth, shells, cloth, paper, etc.) that was incorporating carbon into its body while it lived ... either a plant that was once breathing CO2, or an animal that was eating things that contained carbon (like plants or other animals).  A fossil is not once-living matter.  It is rock that has filled in the impression left by a dead organism.  So fossils themselves may contain very little carbon of any type.]\n\nBut there are other atoms with a *much* longer half-life.  For example potassium-40 (K40) decays into argon-40 (Ar40) with a half-life of 1.26 *billion* years.  So when a rock is created by a volcano, it contains only K40 (as argon is a gas, so any Ar40 present at the time the rock forms escapes from the molten rock before it cools).  But over millions of years this K40 decays to Ar40, which remains trapped in the rock.  So a geologist can dig up a rock from a layer of strata, melt it down, and measure the amount of molten K40 and gaseous Ar40 that is released.  By the ratio of K40 to Ar40 in the rock, the geologist can calculate the age of the rock, in millions of years.  The geologist then also knows the age of anything else that was encased in the same layer of strata as the rock ... such as a fossil.\n\nCarbon-14 dating and potassium-argon dating are two forms of what are called 'radiometric dating'.  Other examples are uranium-lead dating (half-life of 700 million years), and rubidium-strontium dating (half-life of 50 billion years ... which is *very* long, considering that the earth is only 4.5 billion years old).
572825
Estimate 1: The best age for the Earth, 4.54 billion years old, is based on old, presumed single-stage leads coupled with the Pb ratios in troilite from iron meteorites, specifically the Canyon Diablo meteorite. In addition, mineral grains (zircon) with U-Pb ages of 4.4 Ga have recently been reported from sedimentary rocks in west-central Australia.\n\nEstimate 2: 4.6 billion years (4,600,000,000 years)\nRadiometric dating (Uranium, Thorium). Mass spectrometer.\n\nSee sources in links. I'm going to guess in-between those two measurements at about 4,570,000,000 years old.
854963
Check out this website it will tell you all you would ever want to know about radon and any other element.\n\nhttp://www.lenntech.com/Periodic-chart-elements/Rn-en.htm
869096
It is clearly true.\nThe halflife is the amount of time it takes for half of the atoms in a sample to decay. But it does not mean that the other half will be gone in the second period of time, only half of what is remaining.\nSo in 24,000 years you will have 1/2, in another 24,000 years you will have 1/2 of that, or 1/4. In another 24,000 years you will have half of that or 1/8. In another 24,000 years you will have 1/16, and when 100,000 years is past, you will have between 1/16 and 1/32 of the original amount.\n\nThe link has educational illustrations of the process.\n\n;-D It is better not to make any in the first place!
1072258
First consider some scientific estimates or guesses. Not all scientists are going to agree. The Universe or heavens 20 billion years old. The Earth 4.6 billion years old. The Moon 200 to 300 million years younger than the Earth. Dinosaur extinction 65 million years ago. The Ice Age 2.5 million years ago. Oldest evidence of flesh man 7000 to 14000 years old.\n\nThere are 3 earth ages (II Pet.3:5-7), same earth but different ages. We are now in the 2nd earth age. Between Gen.1:1 and Gen.1:2 is a vast amount of time, if time existed. Between these 2 verses is Satan’s rebellion (Rev.12:3-4) and “his tail” drew 1/3 of God’s children. Between these 2 verses also belongs all fossils and remains, such as Dinosaurs.\n\nIn Gen.1:2 we have the of the end of the 1st earth age and the beginning of the 2nd. For clarity Gen.1:2 needs to be divided (see below).\n\n(A) Gen.1:2 And the earth was without form, and void; and darkness was upon the face of the deep. \n\n(B) Gen.1:2 And the Spirit of God moved upon the face of the waters.\n\nIn (A) Gen.1:2 the first occurrence of the word “was” has been corrupted and is “became”. It reads “And the earth became without form, and void”. The end of the 1st earth age.\n\nIn (B) Gen.1:2 we have the beginning of 2nd earth age, the one we live in now. Man did not exist in flesh till this earth age.\n\nBetween (A & B) Gen.1:2 is also a vast amount of time, if time existed. Between (A & B) Gen.1:2  is; a global flood (not Noah’s which was a local flood), the destruction of Atlantis, the breakup of Gondwana Land, and the Ice Age.\n\nTime means nothing to our Father. He is very patient and loves His children. Instead of destroying Satan and 1/3 of His children, He destroyed that first earth age. Now in this 2nd earth age we all are born innocent in the flesh. Father came in the flesh Himself, Jesus Christ, and paid the price for all. Father defeated Satin, that is death, legally. So now His children have a decision, to choose life or to choose death. It’s your decision. Choose life!!
194428
I assume you are using a half-life equation of the form:\nN(t) = N_0*e(-kt) where N(t) is the amount of radium remaining at time t and N_0 is the initial amount of radium. You should really provide this sort of information as the constant k is in no way universal (some people use r or lambda). Decay constant would be a more appropriate term.\n\nSo if the initial amount of radium is N_0 = 1 gram, then\nN(1622) = 0.5 grams(ie. there will only be a half a gram left after 1622 years). Take a natural log and solve for k.\n\nOnce you have k, for the second part let N_0 = 2.3 grams and solve for t where N(t) = 1.7 grams. You're going to need a natural log again for this guy, I trust you know how they work.\n\nAlso I'm pretty sure the previous answer is dead wrong.
330709
The use of uranium, in its natural oxide form, dates back to at least AD 79, when it was used to add a yellow colour to ceramic glazes (yellow glass with 1% uranium oxide was found near Naples, Italy). When this was rediscovered, in the earlier part of the 19th century, the world’s only known source of uranium 'earths' were the old Hapsburg silver mines in Joachimsthal, Bohemia, and the local glassmaking industry kept a tight lid on the secret ingredient and its supply as long as it could.\n\nThe discovery of the element is credited to the German chemist Martin Heinrich Klaproth who in 1789 found uranium in a mineral called pitchblende. It was named after Uranus the planet , which had been discovered eight years earlier by William Herschel. It was first isolated as a metal in 1841 by Eugene-Melchior Peligot. In 1850 the first commercial use of Uranium in glass was developed by Lloyd & Summerfield of Birmingham, England. Uranium was found to be radioactive by French physicist Henri Becquerel in 1896, who first discovered the process of radioactivity with uranium minerals.
1157452
The first 92 elements of the periodic table occur naturally (from hydrogen to uranium).\n\nBTW, in reference to earlier poster, some of the naturally occurring elements (radon, radium, uranium, others) are radioactive, as well.
66333
Earth is way older than radiocarbon dating can determine, i.e. way older than 60,000 years.\n\nSedimental rocks show evidence of the magnetic cycles of earth which reach back into the pre-cambrium.\n\nThorium decay is used for dating ancient rocks, and Thorium decay has been put into relation with these cycles. While not perfect, this method has so far given good evidence.
968818
Shanna and Geo06 have got this just about right.  The only thing I can add is that radiocarbon dating can not be used for more than about 70,000 years ago, and is more accurate for living things that died within the last 8,000 years.\n\nMost geologists measure rock ages in millions, or even billions, of years, so the age of the earth and the age of almost all igneous rocks is well beyond the range of carbon dating.  On top of that, igneous rocks contain very little if any carbon,  so carbon dating is not applicable here.  \n\nSo the only thing carbon 14 can be used for is to determine the time that an exchange of carbon with the atmosphere stopped, ie, the death of a living thing - the third item on your list of choices for your homework.\n\nThe half life of C-14, the radioactive isotope of carbon, is about 5730 years.  Therefore, if you know the ratio between C-14 and C-12 in the atmosphere when the organism died, and you know the ratio now, the difference in the ratio can be calculated backwards, using the half life, to estimate when the organism died. \n\nAtmospheric C-14 has not been in a constant ratio with C-12, as previously thought, so there are some serious problems with the accuracy of C-14 dating.  The problem is that the natural ratio of the carbon isotopes in the atmosphere (carbon dioxide) varies because cosmic ray bombardment of the outer atmosphere produces C-14 but not C-12.  The ratio can be predicted accurately using the ratios in old trees, where the tree rings can be used to accurately determine the age of each ring with its annual ratio, with a maximum of about 8,000 years -that's how old the oldest trees are which can establish a reference ratio.\n\nDating of artifacts is a best guess, the best method is to measure the amount of lichens growing on them, or the age of carbon in ashes found in the same spot.