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 ...

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 ...

For example, the atomic number of sodium is 11. Every sodium atom has 11 protons and 11 electrons. It has 11 positive charges and 11 negative charges. The mass number of an atom is its total ...

Accompanying Lesson Plan: Lesson 3.2: Finding Volume—The Water Displacement Method The chart shows that atomic size and mass for the first 20 elements in the periodic table. The size of the atoms and ...

The proton number (Z) of an atom is the number of protons it contains. All the atoms of a particular element have the same proton number (number of protons). The atoms of different elements have ...