Summer Solstice – June 21st it is directly on top of the pyramid * No shadow at noon * Sun goes down and the seven sisters comes up on the other side * Temple of the Feathered Serpent * Human and Canine Maxillae * Strontium Isotope Analysis Teotihuacan Terms adornos – molded adornments apartment complexes backrack barrios Batres‚ Leopoldo Ciudadela drought Great Goddess Host Figures incensario - incense burner Kaminaljuyu maxillae Pachuca obsidian patio Pennsylvania
Premium Maya civilization Mesoamerican chronology Mesoamerica
volume of sediment in the delta is far greater than it should be‚ given the Red River’s relatively modest size today. He has also shown‚ by studying isotopes of a metal called neodymium‚ that much of this sediment‚ from the Himalayas‚ once came from a block of crust known as the Yangzi craton‚ which underlies Yunnan and Sichuan. The ratio of two isotopes of neodymium differs between rocks from these two places. Between 45m and 23m years ago it shifted from one rich in Yangzi-craton rocks to one dominated
Premium Yunnan River River delta
of products of about 3 to 2‚ for common fissile isotopes.[1][2] Most fissions are binary fissions‚ but occasionally (2 to 4 times per 1000 events)‚ three positively charged fragments are produced in a ternary fission. The smallest of these ranges in size from a proton to an argon nucleus.
Premium Nuclear fission Neutron Uranium
Polonium has more isotopes than any other element‚ all of which are radioactive. Polonium dissolves readily in dilute acids‚ but is only slightly soluble in alkalis. Weight for weight it is about 2.5 x 1011 times as toxic as hydro cyanic acid (HCN). Polonium has been found in tobacco as a contaminant and in uranium ores. Polonium is radioactive and present only in extremely low abundances in the environment. It is quite metallic in nature despite its location beneath oxygen in the periodic table
Premium Chemical element Neutron Radioactive decay
TEST I 1. It represents a long period during which deposition stopped‚ erosion removed previously formed rocks and then deposition resumed. a. Unconformity b. Relative Dating c. Relative Principles d. Inclusion 2. Be established using the law of superposition‚ principle of original horizontality‚ principle of cross-cutting relationships‚ inclusions‚ and unconformities. a. Relative Dating b. Law of Superposition c. Relative Dates 3. What is the principle that layers of sediment are generally deposited
Premium Geology Fossil Neutron
Applications of Radiopharmaceuticals Name: Lew Chien Ai Radiopharmaceuticals are formulations containing radioisotopes‚ which are use internally for therapeutic and diagnostic purposes. Radiopharmaceuticals have modernized the medical field by their ability to provide static as well as dynamic images of internal organs in a noninvasive manner as well as by offering efficacious therapy of certain diseases. Radioisotopes are extensively used in medicine for diagnosis‚ either in
Premium Ionizing radiation Gamma ray Radioactive decay
Chemistry 200 Exam 1 Review Problems 1. Calculate the number of atoms in 10.0 grams of Fe. 2. Give the mass number‚ #protons‚ #neutrons and #electrons for the isotope strontium-88. 3. Calculate the number of moles of carbon in 50.0 g of benzene C6H6 4. A substance is found to be 38.7 % C‚ 9.7 % H and 51.6 % O by mass. Its molar mass is 62.1 g/mole. What is its molecular formula? 5. Name the following: a) Ca(OH)2 b) KCN c) HClO4(aq) d) FeSO4 e) Na2O f) SF6 g)
Premium Oxygen Sodium hydroxide Mass
radiometric dating which tells us the absolute age of rocks. Practically all elements are radioactive to some extent‚ some more than others. Moreover‚ different isotopes of elements are more radioactive than others. Isotopes are forms of a particular atom that varies in the number of neutrons in the nucleus. For instance‚ K-40 is a naturally occurring isotope of Potassium is far more radioactive than its siblings K-39 and K-41 because K-40 is much less stable. K-40 has a half-life of approximately 1.35 billion
Premium Radioactive decay Earth Electron
Principal Quantum # (n from 2n^2 formula for max # e- per level): # specifying the theoretical energy lvl of an elctron in the atom * Avg Atomic Mass: weighted avg of masses of an atom’s isotopes * Isotope: atoms with same # of protons but diff # of neutrons * Isotopic Abundance: % of an isotope in a sample of an element * Nuclear Charge: positive charge on nucleus (# of protons/atomic number) * Position of Outermost Orbital: dist. Btwn nucleus and valence e- (increases down cuz
Free Atom Chemical bond VSEPR theory
ABSTRACT The short and unpredictable nature of the conventional chemical batteries‚ along with the frequent replacements that they require‚ has created an acute need for a reliable‚ longer-lasting and rugged source of energy. Moreover Radars‚ spacecrafts‚ interstellar probes and other advanced communication devices require much larger power than that can be met by conventional energy sources. The solution to long term energy source is the nuclear powered batteries which have a life span of few
Premium Nuclear power Energy development Fuel cell