A chemical element called selenium is included in the periodic table’s oxygen group. It frequently occurs in mixtures with metals like lead, copper, silver, or mercury. The physical characteristics of elements like tellurium and sulphur are blended with them. The Earth’s crust contains 90 parts per billion of this uncommon element. It is a chemical element that belongs to group 16 of the periodic table and is non-metallic.
Allotropic Forms of Selenium
The three most common allotropes of this element are a red amorphous powder, a grey crystalline metal, and a red crystalline substance known as metallic selenium. The grey crystalline form, which is simple to utilise in photocells, conducts electricity more effectively in light than it does in the dark. Water has no effect on it, and it burns in the air and dissolves in intense nitric acid and alkalis.
Uses of Selenium
When used in small amounts, it acts as a decolorizer in the glass. When selenium is used in large quantities, it gives the glass a useful clear red colour in signal lights. It’s also used to make red enamel for steel and ceramics. Also, for vulcanization of rubber to increase abrasion resistance.
Selenium has both a photovoltaic and photoconductive action. As a result, it is useful in photocells, solar cells, and photocopiers. When dealing with chemistry, selenium questions and other elements of knowledge are frequently used.
With an atomic number of 82, lead is a periodic table element. Beginning about 7000 BC, humans have used the metal lead (Pb) for a variety of purposes. With the exception of sulphide and lead glance (PbS), which are used globally to make the metal, the element can be found in trace amounts in a number of minerals.
Properties of Lead
Lead (Pb) is a white, soft, shiny metal that is very malleable. The metal is not only a good conductor of electricity but also has a strong resistance to corrosion. When burned in the air, the metal’s powdered form emits a bluish-white blaze. Lead fluoride is created when fluorine and lead are combined at ambient temperature.
Isotopes of Lead
There are four stable isotopes of lead, with relative abundances of lead-204 (1.48%), lead-207 (22.6%), lead-206 (23.6%), and lead-208 (52.3%). The final byproducts of the three natural decay series of uranium (decays to lead-206), thorium (decays to lead-208), and actinium are three stable lead nuclides (decays to lead-207).
Uses of Lead
The production of storage batteries is one of the numerous additional uses for lead that is most prevalent. In addition to being a component of pewter, type metal, bearing alloys, fusible alloys, and ammunition (shot and bullets), it is utilised in solder.
Sheets and other components composed of lead compounds may be utilised to reduce noise and vibration in large and industrial machines. Lead is utilised as a shielding material for nuclear reactors, particle accelerators, X-ray machines, and storage and transport containers for radioactive materials because it efficiently absorbs electromagnetic radiation of short wavelengths. As a result, since chemistry is all about elements, it makes sense to give questions like lead questions greater weight.