Hydrogen (H) - Element 1 | Properties & Electron Configuration
What is Hydrogen?
Hydrogen (H) is element 1, a nonmetal in period 1, group 1. Its electron configuration is 1s¹.
| Atomic Number | 1 |
| Symbol | H |
| Atomic Mass | 1.008 u |
| Category | Nonmetal |
| Period | 1 |
| Group | 1 |
| Block | s |
| Electron Configuration | 1s¹ |
| Short Config | 1s¹ |
| Electronegativity | 2.2 |
| Atomic Radius | 25 pm |
| Ionization Energy | 1312 kJ/mol |
| Electron Affinity | 73 kJ/mol |
| Phase (STP) | Gas |
Electron Configuration
The full electron configuration of Hydrogen is 1s¹. In noble gas shorthand, this is written as 1s¹.
Hydrogen is a s-block element in group 1, period 1.
Periodic Trends
Electronegativity: Hydrogen has a Pauling electronegativity of 2.2. Within group 1, electronegativity generally decreases down the group.
Atomic Radius: 25 pm. Across period 1, atomic radius generally decreases left to right as nuclear charge increases.
Ionization Energy: 1312 kJ/mol. Ionization energy generally increases across a period and decreases down a group.
View all 118 elements with trend overlays for electronegativity, atomic radius, ionization energy, and electron affinity.
Explore Hydrogen on the Interactive Periodic TableRelated Topics
Lithium (Li)
Properties of Lithium - same group as Hydrogen
Sodium (Na)
Properties of Sodium - same group as Hydrogen
Potassium (K)
Properties of Potassium - same group as Hydrogen
Helium (He)
Properties of Helium - same period as Hydrogen
Is Water Polar?
Polarity of Water - contains Hydrogen
Is Methane Polar?
Polarity of Methane - contains Hydrogen