Atomic Number
12
Element 12
Magnesium (Mg)
Magnesium is a chemical element with symbol Mg and atomic number 12. It is a shiny gray solid which bears a close physical resemblance to the other five elements in the second column of the periodic table.
Atomic Mass
24.305 u
Category
Alkaline Earth Metal
Period
3
Group
Group 2: alkaline earth metals
Phase
solid
Density
1.738 g/cm3
Electron Shells
2, 8, 2
Atomic Structure
Protons: 12. Electrons: 12. Neutrons: Varies by isotope.
Electron configuration: 1s² 2s² 2p⁶ 3s²
Why Magnesium Matters
Magnesium helps connect atomic number 12, alkaline earth metal behavior, period 3 trends, and electron shell structure. Its solid phase, atomic mass of 24.305 u, and electron configuration 1s² 2s² 2p⁶ 3s² make it useful for comparing bonding patterns across the periodic table.
Discovery and Occurrence
Magnesium was discovered 1755 by Joseph Black. Magnesium is a chemical element with symbol Mg and atomic number 12. It is a shiny gray solid which bears a close physical resemblance to the other five elements in the second column of the periodic table.
Safety and Handling Context
Magnesium is presented here for learning and comparison. Pure elements and laboratory compounds can have hazards that depend on dose, form, and setting.
Related Elements
Frequently Asked Questions
- What is the atomic number of Magnesium?
- Magnesium has atomic number 12, which means a neutral atom has 12 protons and 12 electrons.
- What is the chemical symbol for Magnesium?
- The chemical symbol for Magnesium is Mg.
- What category is Magnesium in?
- Magnesium is classified as a alkaline earth metal and sits in period 3 of the periodic table.
Explore Magnesium in 3D
Use the interactive table above to rotate atomic models, compare periodic trends, and move from Magnesium to neighboring elements without losing your place.