Element of the Week: Week 4 - Sodium

Element of the Week Week 4 - Sodium From Anne Marie Helmenstine, Ph.D., your Guide to Chemistry This week's element is sodium, which has the symbol Na from its Latin name,natrium. Sodium is a metal, although you probably haven't seen it in its metallic form. It's very reactive, so sodium metal is kept under oil or kerosene to keep it from igniting in air. Element Facts Periodic Table Entry for Sodium  One fact you may not know about sodium is that it floats on water... well, at least until it spontaneously ignites. Tell me more. Make Invisible Ink Sodium doesn't exist free in nature. Instead, we encounter it in compounds, such as table salt and baking soda (sodium bicarbonate). You can use baking soda to make one type of invisible ink. Soap & Saponification One important reaction involving sodium is saponification, or making soap. Here's the reaction and here are instructions for making soap. Element Photo Gallery Do you want to know what all of the elements look like? Here's a photo gallery that showcases the pure elements. Most of the photographs are public domain so you can download them and use them yourself. More About Sodium Alkali Metals  Sodium is one of the most reactive metals. It belongs to a group of elements called the 'alkali metals', which readily participate in chemical reactions because they have a single electron in their outermost electron shell. The electron is readily removed, so a single atom of an alkali metal usually has a +1 charge. Learn more. Sodium in Fireworks Sodium is a common element in the universe. It burns such a bright yellow that it tends to overpower the colors from other elements. If you add a sodium compound to a flame, such as table salt, you will see bright yellow sparks where the compound is burned. Got Questions Visit the Chemistry Forum  You can ask and answer questions at the chemistry forum. Forum members include anyone interested in chemistry. You'll find scientists, engineers, teachers, students, parents, and other people just like you with an interest in chemistry and the elements. Chemistry Activities for Kids E-Course Are you ready for kid-friendly chemistry activities and games? Each e-course newsletter features safe projects, games or quizzes, and links for additional learning. Learn about the elements, grow crystals, and more! When you sign up you'll get one newsletter a week until you've gotten them all. Sign me up! This email is written by:  Anne Marie Helmenstine, Ph.D.