Xenon is an inert gas in group VIII A of the periodic table with atomic number 54, an atomic weight of 131.3, and a density of 3.06 Mg/m 3. In the solid state it forms an fcc crystal with a melting ...

Atomic number 25, atomic weight 54.9380. Phosphorus (P): Phosphorus is a poisonous, nonmetallic element that helps protect metal surfaces from corrosion. Atomic number 15, atomic weight 30.9738.

Atomic Number and Atomic Mass: Get here the easy notes on atomic number and atomic mass for all the first 30 elements. Know how to calculate atomic mass using atomic number.

Carbon atoms have six protons, so its atomic number is six. Elements also each have a unique atomic mass. The atom's mass primarily comes from the protons and neutrons in the atom's nucleus.