Decay & Half Life

Decay & Half Life

Gentry by [Last Updated: It can be an especially difficult challenge when the Creationist author has professional credentials and has published in mainstream scientific journals. One such individual is Robert Gentry, who holds a Master’s degree in Physics and an honorary doctorate from the fundamentalist Columbia Union College. For over thirteen years he held a research associate’s position at the Oak Ridge National Laboratory where he was part of a team which investigated ways to immobilize nuclear waste. Gentry has spent most of his professional life studying the nature of very small discoloration features in mica and other minerals, and concluded that they are proof of a young Earth. About the Rocks Geologists classify rocks into three main categories – sedimentary, igneous, and metamorphic – based on the way in which they form. Sedimentary rocks are secondary in formation, being the product of precursor rocks of any type. Igneous rocks form from molten material, and are further subdivided into two main categories, the volcanic rocks which form from lava extruded at or near the surface; and plutonic rocks which form from magma, deep within the crust.

Changing Views of the History of the Earth

Leibnitz reworked Descartes’s cosmogony. Protogea was published much later in An essay toward a Natural History of the Earth. Woodward came down fairly strongly for the view that the flood was an act of God that could not be accounted for by normal physical processes. He also postulated hydrological sorting to account for the ordering of fossils.

Uranium ( U or U) is the most common isotope of uranium found in nature, with a relative abundance of 99%. Unlike uranium, it is non-fissile, which means it cannot sustain a chain r, it is fissionable by fast neutrons, and is fertile, meaning it can be transmuted to fissile plutonium U cannot support a chain reaction because inelastic scattering reduces.

April Koch April teaches high school science and holds a master’s degree in education. Learn how scientists determine the ages of rocks and fossils. We’ll explore both relative and numerical dating on our quest to understand the process of geological dating. Along the way, we’ll learn how stratigraphic succession and radioactive decay contribute to the work of paleontologists.

Dating Dinosaur Fossils Consider the following scenario: Paul the Paleontologist is a very famous scientist who has studied dinosaur bones all over the world. Recently, he appeared on the evening news to talk about a new dinosaur he just discovered. The dinosaur is called superus awesomus. Paul says he can tell from the fossils that superus awesomus lived on Earth about million years ago.

Paul is super awesome, so I’m going to take him at his word.

Chemistry Learner

The term Half Life Time was coined in The Half Life Time is the amount of time it takes for half of the atoms in a sample to decay. Half Life is a characteristic of each radioactive isotope. Depending on the isotope, its Half Life may range from a few fractions of a second to several billion years.

A half-life usually describes the decay of discrete entities, such as radioactive atoms. In that case, it does not work to use the definition that states"half-life is the time required for exactly half .

For this example, the term half time might be used instead of"half life”, but they mean the same thing. It varies depending on the atom type and isotope , and is usually determined experimentally. See List of nuclides. The half life of a species is the time it takes for the concentration of the substance to fall to half of its initial value. In non-exponential decay[ edit ] The term “half-life” is almost exclusively used for decay processes that are exponential such as radioactive decay or the other examples above , or approximately exponential such as biological half-life discussed below.

In a decay process that is not even close to exponential, the half-life will change dramatically while the decay is happening. In this situation it is generally uncommon to talk about half-life in the first place, but sometimes people will describe the decay in terms of its “first half-life”, “second half-life”, etc. Biological half-life A biological half-life or elimination half-life is the time it takes for a substance drug, radioactive nuclide, or other to lose one-half of its pharmacologic, physiologic, or radiological activity.

Chemistry Learner

It is ductile, malleable , and capable of taking a high polish. In air the metal tarnishes and when finely divided breaks into flames. It is a relatively poor conductor of electricity.

Learn about different types of radiometric dating, such as carbon dating. Understand how decay and half life work to enable radiometric dating. Play a game that tests your ability to match the percentage of the dating element that remains to the age of the object. Explain the concept of half-life.

The Radiometric Dating Game Radiometric dating methods estimate the age of rocks using calculations based on the decay rates of radioactive elements such as uranium, strontium, and potassium. On the surface, radiometric dating methods appear to give powerful support to the statement that life has existed on the earth for hundreds of millions, even billions, of years. We are told that these methods are accurate to a few percent, and that there are many different methods.

We are told that of all the radiometric dates that are measured, only a few percent are anomalous. This gives us the impression that all but a small percentage of the dates computed by radiometric methods agree with the assumed ages of the rocks in which they are found, and that all of these various methods almost always give ages that agree with each other to within a few percentage points.

Since there doesn’t seem to be any systematic error that could cause so many methods to agree with each other so often, it seems that there is no other rational conclusion than to accept these dates as accurate. However, this causes a problem for those who believe based on the Bible that life has only existed on the earth for a few thousand years, since fossils are found in rocks that are dated to be over million years old by radiometric methods, and some fossils are found in rocks that are dated to be billions of years old.

If these dates are correct, this calls the Biblical account of a recent creation of life into question. After study and discussion of this question, I now believe that the claimed accuracy of radiometric dating methods is a result of a great misunderstanding of the data, and that the various methods hardly ever agree with each other, and often do not agree with the assumed ages of the rocks in which they are found. I believe that there is a great need for this information to be made known, so I am making this article available in the hopes that it will enlighten others who are considering these questions.

Even the creationist accounts that I have read do not adequately treat these issues. At the start, let me clarify that my main concern is not the age of the earth, the moon, or the solar system, but rather the age of life, that is, how long has life existed on earth. Many dating methods seem to give about the same ages on meteorites. Thus radiometric dating methods appear to give evidence that the earth and meteorites are old, if one accepts the fact that decay rates have been constant.

Radioactive Dating Game

Posted on May 1, by The Physicist The original question was: Right off the bat, more dimensions means more freedom of movement. Just one of the subtle economic effects of higher dimensional living.

Take this opportunity to learn about the Canadian province of Saskatchewan. Saskatchewan is located in the prairie region of Canada, bordered by Alberta to the west, Manitoba to the east, Northwest Territories to the north, and the US states of Montana and North Dakota to the south.

The purpose of this chapter is to explain the process of radioactive decay and its relationship to the concept of half-life. Remember that a radionuclide represents an element with a particular combination of protons and neutrons nucleons in the nucleus of the atom. A radionuclide has an unstable combination of nucleons and emits radiation in the process of regaining stability.

Reaching stability involves the process of radioactive decay. A decay, also known as a disintegration of a radioactive nuclide, entails a change from an unstable combination of neutrons and protons in the nucleus to a stable or more stable combination. The type of decay determines whether the ratio of neutrons to protons will increase or decrease to reach a more stable configuration.

It also determines the type of radiation emitted. How do radioactive atoms decay? Radioactive atoms decay principally by alpha decay, negative beta emission, positron emission, and electron capture. How does the neutron-to-proton number change for each of these decay types?

Changing Views of the History of the Earth

Geologists have calculated the age of Earth at 4. But for humans whose life span rarely reaches more than years, how can we be so sure of that ancient date? It turns out the answers are in Earth’s rocks.

The Bush administration invaded Iraq claiming Saddam Hussein had tried to buy yellowcake uranium in Niger. As much of Washington knew, and the world soon learned, the charge was false.

Uranium is a naturally occurring isotope of Uranium metal. It is the only fissile Uranium isotope being able to sustain nuclear fission. Uranium is the only fissile radioactive isotope which is a primordial nuclide existing in the nature in its present form since before the creation of Earth. Uranium makes up around 0.

Uranium is separated from Uranium following the diffusion process using Uranium Hexafluoride UF6 gas. Uranium Symbol The symbol or formula for this radioactive isotope is U. It is also denoted by U Picture 1 — Uranium This fissile material has the following properties: It is a silver colored metal. The molecular weight of this metal is The atomic number for this metal is

Physical Science 7.4f -The Decay of Uranium



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