Can someone me find the element of the periodic table for radium the atomic number is 88 the symbol is ra the atomic mass is 226.025 solve this for me and round 226.025

Find the mass in grams of 1.37x1020 particles of h3po4

Alidded glass container is filled with a colored gas. after a period of time, it is observed that the gas is uniformly spread throughout the box and that the movement has slowed considerably. next, a warm iron plate is carefully placed under the box. why is there resumed movement of the gas in the container?

What is the molar mass of the anhydrous compound? answer using four significant figures. 36.02 g/mol 120.15 g/mol 156.12 g/mol