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 ...

This video is an interactive lesson in calculating an atom’s mass and atomic number. Atoms consist of a nucleus containing protons and neutrons, surrounded by electrons in shells. The numbers of ...

The Atomic Mass Data Center and its electronic bulletin are tools for the exchange of information on experimental masses, evaluation of masses, extrapolation of masses, and theoretical masses. One of ...

Lethal Nuclear Weapon Explosion In The Center Of A City With Big Mushroom Cloud. Mass Destruction. World War Related 3D Animation. mushroom cloud of atom bomb close up of nuclear explosion mushroom, ...

equivalent to the positive charge of the atom) was less than the atomic mass (average mass of the atom). For example, a helium atom has an atomic mass of 4, but an atomic number (or positive ...