Periodic Table of the Elements by WebElements Periodic Table of Elements and Chemistry Lawrence Hall of Science - 24/7 Science How fast does the wind blow? What makes things sticky? Where do insects live and plants grow? What is the best way to clean up the environment? So many questions—and so many ways to find answers! Bridge Builders How Fast Is the Wind Gooo! Filling Without Spilling Parachute Drop Crystals Bird Beaks Sticky Situations Oil Spill How Old is Your Penny? Measure Yourself Where Do Plants Grow? Bug Hunt! Afterschool KidzScience AfterSchool KidzScience™ kits are designed specifically for children in grades 3 - 5 in out-of-school settings. Check Out Science Check Out Science makes doing science with your family easy, no scientific expertise necessary. Explore Your World You don't have to trek through a rainforest, blast off for space, or dive to the deep sea to explore your world. Roadside Heritage Roadside Heritage is an informal science educational project with its origins in the stunning landscape of the Eastern Sierra along the 395 scenic byway. Save Sam! Cat Quiz Bat Quiz Whale Sounds Mr.
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Origin of the Chemical Elements During the process of stellar evolution nuclear fusion reactions take place within a star. These give rise to the formation of the chemical elements. Clues to the processes involved may be deduced from the graph below, which shows the cosmic abundances of elements (y-axis) plotted against atomic number (x-axis). The abundances are measured relative to 1 million silicon atoms and the y-axis is a logarithmic scale. There are three important observations to be made from this graph: The graph has (overall) a smooth trend from left to right, that is from light to heavy elements. It is thought that the early Universe consisted almost entirely of the element hydrogen, with a small amount of helium present too. Early in star development hydrogen is utilised to manufacture the element helium. Elements heavier than iron are formed by the addition of neutrons which are absorbed by the atomic nucleus. You may wish to follow up this section with visits to the following sites:
Elements 4D by DAQRI The Periodic Table . It's Elementary... for a Mad Scientist At the end of the last chapter, we discussed what changing the number of protons in an atom does to the element. Surprise, you have a different element altogether! Now we are going to look at changing the number of electrons to match the number of protons in the atom. After all, there has to be the same number of negative charges as positive charges or the atom will not be neutral. Before we get into electrons, look at your Periodic Table of the Elements. The table has the elements organized into columns and rows. But how do energy levels relate to the Periodic Table?
Welcome to the Chemical Education Digital Library Sustainability & Endangered Elements | Chemistry Description of Contents I. "Rare Earths: Resource Sustainability". Abstract of an article to be published in The Rare Earth Elements: Fundmentals and Applications (October 2012). II. To obtain a copy of the Endangered Elements Periodic Table (shown below) and to get more information on this subject see: III. A. B. C. IV. I. Chapter in The Rare Earth Elements: Fundamentals and Applications, October 2012 David A. Abstract Rare earth elements have unique electronic, optical, luminescent, and magnetic properties that make them critically important in a broad range of products and applications. Keywords: Sustainability, Strategic Elements, Endangered Elements Article Contents: II.
K12 Periodic Table of the Elements