An element has atomic number 12. How many protons does its nucleus contain and which group is magnesium commonly assigned in main-group numbering?
Q1. An element has atomic number 12. How many protons does its nucleus contain and which group is magnesium commonly assigned in main-group numbering?
Answer: 12 protons and Group 2
Explanation: Atomic number equals the number of protons; magnesium has Z=12, so its nucleus contains 12 protons, and it belongs to Group 2 (alkaline earth metals) with two valence electrons.