Westonci.ca is the premier destination for reliable answers to your questions, brought to you by a community of experts. Discover a wealth of knowledge from professionals across various disciplines on our user-friendly Q&A platform. Experience the ease of finding precise answers to your questions from a knowledgeable community of experts.

If an atom has 123 protons, and a mass of 256, what is the atomic number of this element?
A. 123
B. 256
C. 133
D. None of these​