Atomic Number
42
Element 42
Molybdenum (Mo)
Molybdenum is a chemical element with symbol Mo and atomic number 42. The name is from Neo-Latin Molybdaenum, from Ancient Greek Μόλυβδος molybdos, meaning lead, since its ores were confused with lead ores.
Atomic Mass
95.95 u
Category
Transition Metal
Period
5
Group
Group 6: chromium group
Phase
solid
Density
10.28 g/cm3
Electron Shells
2, 8, 18, 13, 1
Atomic Structure
Protons: 42. Electrons: 42. Neutrons: Varies by isotope.
Electron configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹ 4d⁵
Why Molybdenum Matters
Molybdenum helps connect atomic number 42, transition metal behavior, period 5 trends, and electron shell structure. Its solid phase, atomic mass of 95.95 u, and electron configuration 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s¹ 4d⁵ make it useful for comparing bonding patterns across the periodic table.
Discovery and Occurrence
Molybdenum was discovered 1778 by Carl Wilhelm Scheele. Molybdenum is a chemical element with symbol Mo and atomic number 42. The name is from Neo-Latin Molybdaenum, from Ancient Greek Μόλυβδος molybdos, meaning lead, since its ores were confused with lead ores.
Safety and Handling Context
Molybdenum 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 Molybdenum?
- Molybdenum has atomic number 42, which means a neutral atom has 42 protons and 42 electrons.
- What is the chemical symbol for Molybdenum?
- The chemical symbol for Molybdenum is Mo.
- What category is Molybdenum in?
- Molybdenum is classified as a transition metal and sits in period 5 of the periodic table.
Explore Molybdenum in 3D
Use the interactive table above to rotate atomic models, compare periodic trends, and move from Molybdenum to neighboring elements without losing your place.