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 ...

which has a mass of exactly 12. Relative atomic masses do not have units.

Is this the computer that will revolutionize STEM education, get on a postage stamp, and sell tens of millions of units? No. The answer is no. While I’m not allowed to call the Atomic Pi ...

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 ...