Coal Tar. Tar derived from both coal and wood (e.g., juniper, pine) are both used for medicinal purposes. However, coal tar is the type used most commonly to treat psoriasis. Tar can help slow the rapid growth of skin cells and restore the skin's appearance. In addition, it can help reduce the inflammation, itching and scaling of psoriasis. Tar products can vary dramatically from brand to brand.
Quick Answer. The lightest element on the periodic table is hydrogen. The atomic weight of hydrogen is 1.00794 and the atomic number is 1. Hydrogen is the most abundant element on the periodic table with 75 percent of the mass of the universe consisting of hydrogen. Continue Reading.
The lightest chemical elements are hydrogen and helium, both created by Big Bang nucleosynthesis during the first 20 minutes of the universe in a ratio of around 3:1 by mass (or 12:1 by number of atoms), along with tiny traces of the next two elements, lithium and beryllium.he mass number of an element, A, is the number of nucleons (protons and neutrons) in the atomic nucleus. Different isotopes of a given element are distinguished by their mass numbers, which are conventionally written as a superscript on the left hand side of the atomic symbol (e.g., 238 U).