The periodic table of chemical elements, often called the periodic table, organizes all discovered chemical elements in rows (called periods) and columns (called groups) according to increasing atomic ...

These elements are building blocks of matter and everything around us is made up of them. There are 118 elements in the periodic table, each with a unique symbol and atomic number.

The term ‘weighted mean mass’ takes into account the different contribution of each isotope to the overall mass. Relative atomic mass is not the same as mass number. Mass numbers close mass ...

For example, the atomic number of chlorine is 17. Every chlorine atom has 17 protons and 17 electrons. It has 17 positive charges and 17 negative charges, meaning that it is neutral overall.

Iron is the main ingredient in various forms of iron and steel, but the various types of metals contain other elements as well. Sometimes these elements are unwanted; other times they're ...

This Q-value calculation programme allows you to calculate reaction Q-values and threshold energies and decay Q values based on the 1995 Update to the Atomic Mass Evaluation and to retrieve other ...