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.
Hydrogen is the simplest element of all, and the lightest. It is also by far the most common element in the Universe. Over 90 percent of the atoms in the Universe are hydrogen. In its commonest form, the hydrogen atom is made of one proton, one electron, and no neutrons. Hydrogen is the only element that can exist without neutrons. Hydrogen is a colorless, odorless gas which exists, at standard temperature and pressure, as diatomic molecules, H2.