The food-grade items that have been brought into the lab are considered laboratory chemicals and are for lab use only.…
3. Put the different samples in separate cups and count the number of beans in each cup; write those numbers in the data table.…
Hypothesis according to Aristotle (350 BC): All matter consists of the elements earth, air, fire, and water.…
3. Explain which would be the best isotope from the Isotope Half-Life Chart to measure a 3 billion year old specimen.Rubidium isotope would be the best isotope to use for that measurement because it contains the most years that would be needed to measure that span. Even with the help of this isotope the task would still be rather difficult to make precise.…
2. Calculate the percent abundance of each isotope by dividing its number of particles by the total number of particles and multiplying by 100. Record your…
You may have noticed on the periodic table that the atomic mass of an element is…
Most of the atom’s mass is concentrated in a small region, the nucleus, at the centre of the atom.…
3. Explain which would be the best isotope from the Isotope Half-Life Chart to measure a 3 billion year old specimen.…
Scientists have settled on the age of the earth of about 4.6 billion years as a result of research started almost 50 years ago. This conclusion was based upon carefully designed and conducted experiments that compared the ratios in rock samples of parent elements to daughter elements ( some of which would have been from radioactive decay of the parent, some of which may have been present in the sample at the time of formation). Since radioactive decay is known to occur at a constant rate, the age of a rock can be determined from the ratio of the parent element to the daughter element. The concerns about these dating methods were exactly the same that creationists continue to raise - presence of the daughter element at the time the rock was formed and possible loss / gain of either the parent or daughter element at some point in the history of the rock. For this reason, the tests were designed to account for those possibilities.…
However, in 1913 the first geologic time scale was presented by Arthur Holmes; this was deciphered after the discovery of radioactivity by Henri Becquerel in 1896. Holmes used radioactivity to deduce that the Precambrian Era was between 4.6 billion-544 million years ago; the first milestone is the formation of Earth, and the second milestone is the beginning of life. As science and technology progresses scientists have a more exact date, which is, that the Earth is 4.543 billion years old. Scientists formulated the Precambrian era by practicing radioactive dating: knowing the number of radioactive parent atoms present when a rock formed and the number present now. The number of parent atoms initially present is the number present now plus the number of daughter atoms formed by the decay, both of which are amounts that can be measured. Moreover, another method that was used to determine when Earth formed was by reporting the proportion of lead types located in meteorites and comparing them to lead proportions located in other rocks on the Earth and other meteorites. Clearly, using radioactive dating and the comparison of rocks was essential factors in answering the questions on Earth's…
Atoms, molecules and elements are the building blocks of everything we can see, hear, and touch. Though not visible to the naked eye, it is the combination of millions of these tiny substances that make us who and what we are today. Many elements make up the world around us, and each element reacts differently to its surroundings.…
The goal of this course is to provide an effective science education to students who are not…
-An Isotope is an Atom with the same number of protons, but differing numbers of neutrons. Isotopes are different forms of a Single element.…
The half-life of the isotope was considered to be the time at which the activity has dropped to ½ its original value and was given the symbol, t1/2. Calculation of the half-life was determined with the equation ln [ (A)0 / (A) t1/2 ] = kt1/2 , or, rearranged: ln 2 = kt1/2.…
“Radiometric age-dating is based on the fact that every radioactive element decays. The original or “parent” element emits radiation and particles until the loss thereof transforms it into a stable “daughter” element. A series of transformations into other radio-active elements marks its unparalleled pattern and rate of decay until it reaches stability (Think Quest).” “The decay of radioactive elements occurs at different rates, depending on the specific isotope. These rates are stated in terms of half-lives. One half-life is the amount of time required for ½ of the original atoms in a sample to decay (O'Neil).” Radiometric methods provide one of the most important ways to date fossils. The main types of radiometric dating are Potassium-argon, carbon-14 or radiocarbon, thermoluminescence, and electron-spin-resonance. Potassium-argon dating is used for dating volcanic rocks associated with fossil material. It can date better for older specimens but when used for younger specimens it can give a wrong date. You have to be careful and use the right method for the selected…