Argon is an inert gas in group VIII A of the periodic table with atomic number 18, an atomic weight of 39.948, and a density of 1.40 Mg/m 3. In the solid state it forms an fcc crystal with a melting ...

For example, the mass number of both argon atoms and calcium atoms is 40. The atomic number of a sodium atom is 11 and its mass number is 23. Calculate the number of protons, neutrons and ...

There are 118 elements in the periodic table, each with a unique symbol and atomic number. Symbol: A one or two-letter abbreviation used to represent the element. Atomic number: The number of ...