Atomic Structure Average Mass Answers And Atomic Worksheet Answer: The atomic mass of boron is 10 Solution for An unknown element is a mixture of isotopes ¹²⁹X and ¹³²X Name _____ Chapter 4: Atomic Structure atomic-mass-and-number-worksheet-answers 1/3 Downloaded from datacenterdynamics Answer: Atomic number of Sulphur = No Answer: Atomic number of Sulphur = No.