Johannes van der Waals developed a model to explain the behavior of liquids and solids that reflected the size of the atoms or molecules and the strength of the forces between these atoms or molecules. The weak intermolecular forces in…
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Uranium, with an atomic number of 92, is a metallic chemical element found amongst the periodic table. It is fitted into the actinide series of the table and has the symbol U. Its neutrons vary from 141 to 146. It…
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The Periodic Table of the Elements is a display of the 118 known chemical elements. It is organized according to the repeating properties of the elements in each group on the table, hence the name periodic. Classifying these elements has…
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The most common way to tell if a liquid is an acid or a base is to submit it to a litmus test. A drop of a liquid acid substance on a test sheet of litmus paper will turn red; if…
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While the cell is the basic building block of living things, the atom is the basic building block of matter. Everything from the largest galaxy to the amoeba consists of a collection of atoms. While our understanding of the atom…
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The first person to try to organize the chemical elements into patterns was Johann Dobereiner. He grouped families of elements into triads in order of atomic mass in 1828. Elements were grouped into families because of the similarities in reaction…
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If you look at a chart of the periodic table, two rows of elements appear separate from the main table. These two rows comprise the lanthanide (or lanthanoid) group and the actinide (or actinoid) group. The elements in these two…
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The Rutherford gold-foil experiment, although actually developed and carried out in 1909 by members of Rutherford’s research team, drove what was perhaps the most important paradigm shift concerning the structure of matter known to history. Early concepts of the composition…
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The Law of Conservation of Mass was established as a basic rule of chemistry from Antoine Lavoisier’s work on combustion. The Law of Conservation of Mass says that matter may be changed from one form to another but cannot be created…
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The Nobel Prize winner Niels Henrik David Bohr was born in Copenhagen, Denmark on October 7 1885. The middle of three children, his father Christian Bohr was the professor of physiology at Copenhagen University and his mother was the daughter…
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