Hello and welcome to Teach Kids Chemistry! Today, we will be exploring the fascinating element known as selenium. Selenium is a nonmetallic element that is essential to life in small amounts, but can be toxic in larger amounts. It has a variety of uses, from being used in glassmaking to being added to shampoos and conditioners for its beneficial effects on hair. Join us as we dive into the world of selenium and learn about its properties, uses, and importance in our daily lives.
The Periodic Element Selenium Overview
Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal with an atomic mass of 78.96 u. Selenium has 34 protons and 34 electrons in its atomic structure. The number of neutrons in selenium can vary, with the most common isotope having 45 neutrons. It is located in period 4 and group 16 of the periodic table. Selenium is a solid at room temperature and is classified as a nonmetal.Selenium has an electronegativity of 2.55 and a specific heat capacity of 0.767 J/g·K. Its melting point is 217 °C and its boiling point is 685 °C. The density of selenium is 4.81 g/cm³. Selenium is an essential trace element for humans and animals, and it is used in various industries such as electronics, glassmaking, and metallurgy. It is also used in dietary supplements and in the treatment of certain medical conditions.
Everyday objects that contain the periodic element selenium?
There are many everyday objects that contain chemicals or chemical compounds. For example, water is a chemical compound made up of two hydrogen atoms and one oxygen atom (H2O). Salt, which is commonly used in cooking, is a compound made up of sodium and chloride ions (NaCl). Baking soda, which is used in baking and cleaning, is a compound made up of sodium, hydrogen, carbon, and oxygen (NaHCO3). Vinegar, which is used in cooking and cleaning, is a solution of acetic acid (CH3COOH) and water. These are just a few examples of everyday objects that contain chemicals or chemical compounds.
Differences in the periodic element selenium across states of matter
The state of an element can vary greatly depending on its temperature and pressure. At standard temperature and pressure (STP), most elements are either solids or gases. Solids have a fixed shape and volume, while gases have neither. As temperature and pressure increase, some solids can become liquids, which have a fixed volume but take the shape of their container. As temperature and pressure continue to increase, some liquids can become gases, which have neither a fixed shape nor volume. At extremely high temperatures and pressures, some gases can become plasmas, which are highly ionized and conductive. Plasmas are often found in stars and lightning bolts, and have unique properties such as the ability to emit light.
Is the periodic element selenium dangerous or radioactive?
Selenium is a non-metallic chemical element with the symbol Se and atomic number 34. It is not considered a dangerous or radioactive element. In fact, selenium is an essential nutrient for humans and animals in small amounts, but can be toxic in larger amounts. It is commonly found in soil, water, and some foods, and is used in various industrial applications such as glass production and electronics. Overall, selenium is a relatively safe and important element in both biological and industrial contexts.
Is the periodic element selenium rare and expensive?
Selenium is not considered a rare or expensive element. It is actually quite abundant in the Earth’s crust, with an estimated concentration of 0.05 parts per million. It is commonly found in minerals such as pyrite, galena, and sphalerite. Selenium is also produced as a byproduct of copper refining. In terms of cost, selenium is relatively inexpensive compared to other elements. As of 2021, the cost of selenium is around $0.20 per gram, making it an affordable element for use in various applications.
Learn about all the elements with a periodic table!