Yearly Archives: 2019


Electronegativity trend of the periodic table
Electronegativity is a measure of how easily an atom attracts a pair of electrons to form a chemical bond. A high electronegativity value means an atom readily attracts electrons to form a chemical bond with another atom. A low electronegativity value means an atom readily donates electrons to form a […]

Electronegativity Definition and Trend


Hydrogen Isotopes
Isotopes are forms of an element that have different numbers of neutrons. All isotopes of an element have the same atomic number and number of protons, but they have different atomic masses from each other. Isotopes of an element share similar chemical properties, but have different nuclear properties. Every element […]

What Is an Isotope? Definition and Examples


Periodic Table of Radioactive Elements 1
Technetium is a radioactive element, with no stable isotopes. With an atomic number of 43, it is the lightest unstable element. All of the elements surrounding it on the periodic table have at least one stable isotope. What is it about technetium that makes it special? The short answer is […]

Why Is Technetium Radioactive?




CPK-Jmol Periodic Table
Chemistry departments often have kits of plastic balls to stick together to represent atoms and their arrangement in molecules. These kits come with several different colors to easily distinguish one element from another. The choice of color for each atom is not arbitrary. The color code of these atoms is known as CPK colors.

Molecule Atom Colors – CPK Colors