Hydrogen is a gas in group IA of the periodic table with atomic number 1, an atomic weight of 1.008, and a density of 0.071. Hydrogen forms an hcp solid at low temperatures, melting at - 259.2 C and ...

Chlorine is a halogen in group VII A of the periodic table with atomic number 17, an atomic weight of 35.45, and a density of 1.56 Mg/m 3. In the solid state it forms a tretragonal crystal with a ...