This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Fundamentals in Radiology, Subject name: Radiology
Maximum scattering in X-ray plate occurs in 
Select and explain. 
A. Carbon, B. Mercury, C. H+, D. Ca++
A: Carbon
Answer: A: Carbon 
Explanation: Scattering is directly propoional to the number of electrons available in the outer shell of the atom. option A : Carbon has 4 outer shell electrons option B : mercury has 2 outer shell electrons option C : H+ has 0 outer shell electrons option D : Ca++ has 0 outer shell electrons