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Hydrogen Orbitals Calculator

Calculate hydrogen orbitals with our free science calculator. Uses standard scientific formulas with unit conversions and explanations.

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Physics

Hydrogen Orbitals Calculator

Calculate hydrogen atom orbital properties including energy levels, orbital radii, angular momentum, nodes, and spectral transition wavelengths. Supports hydrogen-like ions with any atomic number Z.

Last updated: December 2025

Calculator

Adjust values & calculate
n = 2
l = 1

Range: 0 to 1 (s=0, p=1, d=2, f=3)

m = 0

Range: -1 to +1

Z = 1

Z=1 for hydrogen, Z=2 for He+, Z=3 for Li2+

Orbital: 2p
-3.400000 eV
Ionization Energy: 3.400000 eV
Orbital Radius
211.67 pm
0.2117 nm
Angular Momentum
1.4142 hbar
Radial Nodes
0
Angular Nodes
1
Total Nodes
1
Sublevel Degeneracy
6
Total Level Degeneracy
8
Electron Velocity
1093.60 km/s
0.3645% of c
Transition to Ground
121.57 nm
Your Result
2p: E = -3.400000 eV | r = 211.67 pm | Nodes: 1
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Formula

E_n = -13.6 * Z^2 / n^2 eV

Where E_n is the energy of level n in electron volts, Z is the atomic number, and n is the principal quantum number. The orbital radius is r = a0 * n^2 / Z where a0 = 52.9 pm is the Bohr radius. Angular momentum magnitude is L = hbar * sqrt(l*(l+1)).

Last reviewed: December 2025

Worked Examples

Example 1: Hydrogen 2p Orbital Properties

Calculate the energy, orbital radius, and angular momentum for an electron in the 2p orbital (n=2, l=1, m=0) of hydrogen (Z=1).
Solution:
Energy = -13.6 * 1^2 / 2^2 = -13.6 / 4 = -3.4 eV Orbital radius = a0 * n^2 / Z = 52.9 pm * 4 / 1 = 211.6 pm Angular momentum = hbar * sqrt(l*(l+1)) = hbar * sqrt(2) = 1.414 * hbar z-component = m * hbar = 0 Radial nodes = n - l - 1 = 2 - 1 - 1 = 0 Angular nodes = l = 1 Degeneracy of 2p = 2*(2*1+1) = 6
Result: E = -3.4 eV | r = 211.6 pm | L = 1.414 hbar | 0 radial nodes, 1 angular node

Example 2: He+ Ion Ground State

Calculate the properties of the ground state (1s) of a He+ ion (Z=2). Compare with hydrogen.
Solution:
Energy = -13.6 * 2^2 / 1^2 = -13.6 * 4 = -54.4 eV (4x hydrogen) Orbital radius = a0 * 1^2 / 2 = 52.9 / 2 = 26.45 pm (half of hydrogen) Ionization energy = 54.4 eV Velocity = 2 * 2188 km/s = 4376 km/s Wavelength to n=2: 1240 / (13.6 * 4 * (1 - 1/4)) = 1240 / 40.8 = 30.4 nm (EUV)
Result: E = -54.4 eV | r = 26.45 pm | Ionization = 54.4 eV | v = 4376 km/s
Expert Insights

Background & Theory

The Hydrogen Orbitals Calculator applies the following established principles and formulas. Physics is the fundamental natural science concerned with matter, energy, and the interactions between them. Classical mechanics, founded on Newton's three laws of motion, provides the framework for analyzing the motion of objects. The first law states that an object remains at rest or in uniform motion unless acted upon by a net external force. The second law quantifies this relationship: F = ma, where force equals mass times acceleration in SI units of newtons (N = kgยทm/sยฒ). The third law establishes that every action produces an equal and opposite reaction. Kinematics describes motion without reference to its causes. The four fundamental equations relate displacement s, initial velocity u, final velocity v, acceleration a, and time t: v = u + at, s = ut + ยฝatยฒ, vยฒ = uยฒ + 2as, and s = ยฝ(u + v)t. These assume constant acceleration and are foundational for solving projectile motion, free fall, and linear dynamics problems. Energy conservation underpins much of physics. Kinetic energy is KE = ยฝmvยฒ, where m is mass in kilograms and v is speed in meters per second. Gravitational potential energy is PE = mgh, where g โ‰ˆ 9.81 m/sยฒ near Earth's surface and h is height in meters. The work-energy theorem states that the net work done on an object equals its change in kinetic energy: W = ฮ”KE. Electricity and circuits rely on Ohm's law: V = IR, where voltage V is in volts, current I in amperes, and resistance R in ohms. Electrical power is P = IV = IยฒR = Vยฒ/R, measured in watts. Wave mechanics connects frequency f, wave speed v, and wavelength ฮป through f = v/ฮป, with frequency in hertz (Hz). Pressure is defined as force per unit area, P = F/A, in pascals (Pa = N/mยฒ). The ideal gas law PV = nRT links pressure, volume, moles n, the gas constant R = 8.314 J/(molยทK), and absolute temperature in kelvin. Gravitational force between two masses follows Newton's law of universal gravitation: F = Gmโ‚mโ‚‚/rยฒ, where G = 6.674ร—10โปยนยน Nยทmยฒ/kgยฒ is the gravitational constant.

History

The history behind the Hydrogen Orbitals Calculator traces back through the following developments. The history of physics spans over two millennia, beginning with the natural philosophy of ancient Greece. Aristotle (384โ€“322 BCE) proposed that all matter consisted of four elements and that objects moved toward their natural place, with heavier objects falling faster than lighter ones. While largely incorrect, his systematic approach to explaining nature dominated Western thought for nearly 2,000 years. The Scientific Revolution overturned Aristotelian physics. Galileo Galilei (1564โ€“1642) performed groundbreaking experiments on inclined planes and falling bodies, demonstrating that all objects fall with the same acceleration regardless of mass, and established the principle of inertia. His use of mathematics to describe motion was revolutionary. Isaac Newton synthesized these developments in his landmark Principia Mathematica (1687), laying out the three laws of motion and the law of universal gravitation. Newton's framework unified terrestrial and celestial mechanics, explaining planetary orbits with the same equations governing a falling apple. His calculus provided the mathematical language for expressing rates of change. The 19th century brought two major theoretical achievements. James Clerk Maxwell formulated his equations of electromagnetism between 1861 and 1862, unifying electricity, magnetism, and optics, and predicting the existence of electromagnetic waves traveling at the speed of light. Thermodynamics was developed by Carnot, Clausius, and Kelvin, establishing the laws governing heat, work, and entropy. The 20th century produced two revolutions that fundamentally altered the classical picture. Albert Einstein published the special theory of relativity in 1905, showing that space and time are not absolute but relative to the observer, and that mass and energy are equivalent via E = mcยฒ. His general theory of relativity in 1915 reinterpreted gravity as the curvature of spacetime. Simultaneously, quantum mechanics emerged from the work of Planck, Bohr, Heisenberg, and Schrรถdinger, revealing that at atomic scales energy is quantized and particles exhibit wave-particle duality. These developments culminated in the Standard Model of particle physics, which describes all known fundamental particles and three of the four fundamental forces.

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Frequently Asked Questions

Hydrogen orbitals are the quantum mechanical wavefunctions that describe the probability distribution of the electron in a hydrogen atom or hydrogen-like ion. They are the exact analytical solutions to the Schrodinger equation for the Coulomb potential and form the foundation of all atomic physics and chemistry. Each orbital is characterized by three quantum numbers: principal (n), angular momentum (l), and magnetic (m), which determine the energy, shape, and orientation of the electron distribution. Hydrogen orbitals are important because they serve as the basis for understanding multi-electron atoms, chemical bonding, molecular structure, and spectroscopy across all of chemistry and materials science.
In the hydrogen atom, all orbitals with the same principal quantum number n have the same energy regardless of the l and m values. This means the 2s and 2p orbitals have identical energy, and the 3s, 3p, and 3d orbitals are all degenerate. This accidental degeneracy is unique to the pure Coulomb potential and arises from a hidden symmetry related to the Laplace-Runge-Lenz vector. The total degeneracy of level n is 2n squared (including spin). In multi-electron atoms, electron-electron repulsion breaks this degeneracy, causing subshells with different l values to have different energies. This lifting of degeneracy explains the structure of the periodic table and chemical properties.
Nodes are regions where the wavefunction (and therefore the probability of finding the electron) is exactly zero. Radial nodes are spherical surfaces where the radial wavefunction crosses zero, and their number equals n minus l minus 1. Angular nodes are planes or cones where the angular wavefunction is zero, and their number equals l. The total number of nodes (excluding the node at infinity) is always n minus 1. For example, the 3d orbital has zero radial nodes and two angular nodes (total of 2), while the 3s orbital has two radial nodes and zero angular nodes (also total 2). Node structure determines the orbital shape and influences chemical bonding properties.
When an electron transitions between energy levels in hydrogen, it emits or absorbs a photon with energy equal to the difference between the levels. The energy formula E equals negative 13.6 eV times Z squared divided by n squared predicts discrete spectral lines organized into series. The Lyman series (transitions to n=1) produces ultraviolet light, the Balmer series (to n=2) produces visible light, and the Paschen series (to n=3) produces infrared radiation. These spectral lines were observed experimentally before quantum mechanics and provided crucial evidence for the quantized nature of atomic energy levels. The hydrogen spectrum remains the most precisely measured and theoretically understood atomic spectrum.
Hydrogen-like ions are atoms or ions with only one electron, such as He+ (Z=2), Li2+ (Z=3), and Be3+ (Z=4). Their energy levels scale as Z squared times the hydrogen values, so He+ has four times the binding energy of hydrogen. Orbital radii scale as 1/Z, making the orbitals more compact. The velocity scales as Z times the hydrogen value. These scaling relationships are exact because the single-electron Coulomb problem has an analytical solution for any Z. Hydrogen-like ions are important in plasma physics, astrophysics, and spectroscopy. The study of highly charged hydrogen-like ions (large Z) tests quantum electrodynamics corrections to high precision.
Orbital angular momentum in hydrogen is quantized with magnitude equal to hbar times the square root of l times (l plus 1). The z-component is quantized as m times hbar, where m ranges from minus l to plus l. This quantization means the angular momentum vector can only take specific orientations relative to a chosen axis, a phenomenon called space quantization. The angular momentum determines the orbital shape, the number of angular nodes, the magnetic properties of the atom, and selection rules for transitions. In a magnetic field, different m values acquire different energies (Zeeman effect), splitting spectral lines and demonstrating the reality of space quantization experimentally.
Educational Note: This calculator is provided for educational and informational purposes. Results are based on the formulas and inputs provided. Always verify important calculations independently. NovaCalculator processes calculator inputs client-side; optional analytics follow visitor consent settings. ยฉ 2024โ€“2026 NovaCalculator.

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Formula

E_n = -13.6 * Z^2 / n^2 eV

Where E_n is the energy of level n in electron volts, Z is the atomic number, and n is the principal quantum number. The orbital radius is r = a0 * n^2 / Z where a0 = 52.9 pm is the Bohr radius. Angular momentum magnitude is L = hbar * sqrt(l*(l+1)).

Worked Examples

Example 1: Hydrogen 2p Orbital Properties

Problem: Calculate the energy, orbital radius, and angular momentum for an electron in the 2p orbital (n=2, l=1, m=0) of hydrogen (Z=1).

Solution: Energy = -13.6 * 1^2 / 2^2 = -13.6 / 4 = -3.4 eV\nOrbital radius = a0 * n^2 / Z = 52.9 pm * 4 / 1 = 211.6 pm\nAngular momentum = hbar * sqrt(l*(l+1)) = hbar * sqrt(2) = 1.414 * hbar\nz-component = m * hbar = 0\nRadial nodes = n - l - 1 = 2 - 1 - 1 = 0\nAngular nodes = l = 1\nDegeneracy of 2p = 2*(2*1+1) = 6

Result: E = -3.4 eV | r = 211.6 pm | L = 1.414 hbar | 0 radial nodes, 1 angular node

Example 2: He+ Ion Ground State

Problem: Calculate the properties of the ground state (1s) of a He+ ion (Z=2). Compare with hydrogen.

Solution: Energy = -13.6 * 2^2 / 1^2 = -13.6 * 4 = -54.4 eV (4x hydrogen)\nOrbital radius = a0 * 1^2 / 2 = 52.9 / 2 = 26.45 pm (half of hydrogen)\nIonization energy = 54.4 eV\nVelocity = 2 * 2188 km/s = 4376 km/s\nWavelength to n=2: 1240 / (13.6 * 4 * (1 - 1/4)) = 1240 / 40.8 = 30.4 nm (EUV)

Result: E = -54.4 eV | r = 26.45 pm | Ionization = 54.4 eV | v = 4376 km/s

Frequently Asked Questions

What are hydrogen orbitals and why are they important?

Hydrogen orbitals are the quantum mechanical wavefunctions that describe the probability distribution of the electron in a hydrogen atom or hydrogen-like ion. They are the exact analytical solutions to the Schrodinger equation for the Coulomb potential and form the foundation of all atomic physics and chemistry. Each orbital is characterized by three quantum numbers: principal (n), angular momentum (l), and magnetic (m), which determine the energy, shape, and orientation of the electron distribution. Hydrogen orbitals are important because they serve as the basis for understanding multi-electron atoms, chemical bonding, molecular structure, and spectroscopy across all of chemistry and materials science.

Why are hydrogen atom energy levels degenerate?

In the hydrogen atom, all orbitals with the same principal quantum number n have the same energy regardless of the l and m values. This means the 2s and 2p orbitals have identical energy, and the 3s, 3p, and 3d orbitals are all degenerate. This accidental degeneracy is unique to the pure Coulomb potential and arises from a hidden symmetry related to the Laplace-Runge-Lenz vector. The total degeneracy of level n is 2n squared (including spin). In multi-electron atoms, electron-electron repulsion breaks this degeneracy, causing subshells with different l values to have different energies. This lifting of degeneracy explains the structure of the periodic table and chemical properties.

What are radial and angular nodes in hydrogen wavefunctions?

Nodes are regions where the wavefunction (and therefore the probability of finding the electron) is exactly zero. Radial nodes are spherical surfaces where the radial wavefunction crosses zero, and their number equals n minus l minus 1. Angular nodes are planes or cones where the angular wavefunction is zero, and their number equals l. The total number of nodes (excluding the node at infinity) is always n minus 1. For example, the 3d orbital has zero radial nodes and two angular nodes (total of 2), while the 3s orbital has two radial nodes and zero angular nodes (also total 2). Node structure determines the orbital shape and influences chemical bonding properties.

How do hydrogen orbital energies relate to atomic spectra?

When an electron transitions between energy levels in hydrogen, it emits or absorbs a photon with energy equal to the difference between the levels. The energy formula E equals negative 13.6 eV times Z squared divided by n squared predicts discrete spectral lines organized into series. The Lyman series (transitions to n=1) produces ultraviolet light, the Balmer series (to n=2) produces visible light, and the Paschen series (to n=3) produces infrared radiation. These spectral lines were observed experimentally before quantum mechanics and provided crucial evidence for the quantized nature of atomic energy levels. The hydrogen spectrum remains the most precisely measured and theoretically understood atomic spectrum.

What are hydrogen-like ions and how do their properties scale with Z?

Hydrogen-like ions are atoms or ions with only one electron, such as He+ (Z=2), Li2+ (Z=3), and Be3+ (Z=4). Their energy levels scale as Z squared times the hydrogen values, so He+ has four times the binding energy of hydrogen. Orbital radii scale as 1/Z, making the orbitals more compact. The velocity scales as Z times the hydrogen value. These scaling relationships are exact because the single-electron Coulomb problem has an analytical solution for any Z. Hydrogen-like ions are important in plasma physics, astrophysics, and spectroscopy. The study of highly charged hydrogen-like ions (large Z) tests quantum electrodynamics corrections to high precision.

What is the significance of orbital angular momentum in hydrogen?

Orbital angular momentum in hydrogen is quantized with magnitude equal to hbar times the square root of l times (l plus 1). The z-component is quantized as m times hbar, where m ranges from minus l to plus l. This quantization means the angular momentum vector can only take specific orientations relative to a chosen axis, a phenomenon called space quantization. The angular momentum determines the orbital shape, the number of angular nodes, the magnetic properties of the atom, and selection rules for transitions. In a magnetic field, different m values acquire different energies (Zeeman effect), splitting spectral lines and demonstrating the reality of space quantization experimentally.

References

Reviewed by Manoj Kumar, Mathematics Educator ยท Editorial policy