Orbit vs Orbital: Key Differences Table with Diagrams and Examples
The difference between orbit and orbital is fundamental for mastering atomic structure questions in JEE Main Chemistry. Orbits are defined as fixed circular paths for electrons around the nucleus, as proposed by Bohr's atomic model. In contrast, orbitals refer to regions in an atom where there is a high probability of finding an electron, as predicted by the quantum mechanical model. Understanding this distinction helps avoid common exam mistakes and deepens conceptual clarity on topics like electronic configuration and quantum numbers.
Difference Between Orbit and Orbital: Comparison Table
| Criteria | Orbit | Orbital |
|---|---|---|
| Basis | Bohr Model; fixed circular path | Quantum Model; probable region |
| Definition | Definite path in which electrons revolve | 3D space with high electron probability |
| Shape | Always circular or elliptical | Varies (spherical, dumbbell, etc.) |
| Maximum Electrons | 2n2 electrons per orbit (n = shell no.) | Maximum 2 electrons per orbital |
| Distinction | Numbered as shells (K, L, M...) | Named by type (s, p, d, f) |
| Discovery | Niels Bohr (1913) | Schrödinger’s equation (1926) |
Recognising these key differences between orbit and orbital simplifies topics such as shell filling, quantum numbers, and electron configuration for JEE aspirants.
Orbits Explained: Bohr’s Atomic Model
An orbit is the fixed, circular path suggested by Niels Bohr, where electrons revolve around the nucleus at set distances. Each orbit has a specific energy and is associated with quantum number n. These are also called "shells"—like K, L, M, N—for n = 1, 2, 3, 4. The Bohr model successfully explains the hydrogen atom’s spectrum but cannot explain multi-electron atoms or fine details.
- Orbits are defined by quantised angular momentum (mvr = nh/2π).
- Applicable mainly for hydrogen and hydrogen-like ions.
- Lacks explanation for electron cloud or varied shapes in atoms with more than one electron.
- Obsolete for detailed or advanced atomic structure questions.
- Bohr’s postulates set the stage for further quantum developments.
Despite limitations, orbits provide foundational terminology for shell numbers, energy levels, and electron transitions in basic exam problems.
Orbitals Explained: Quantum Mechanical Model
Orbitals are the cornerstone of the quantum mechanical view of the atom. An orbital is a region in three-dimensional space where the probability of finding an electron is highest (about 90%). This concept emerged from Schrödinger’s equation, which uses quantum numbers (n, l, ml, ms) to define each orbital’s energy, orientation, and shape.
- s orbitals: spherical shape; found in all shells (n ≥ 1).
- p orbitals: dumbbell-shaped; exist for n ≥ 2 (px, py, pz).
- d orbitals: cloverleaf or cross shapes; available from n ≥ 3.
- f orbitals: complex shapes; present from n ≥ 4.
- Each orbital supports only 2 electrons, obeying the Pauli Exclusion Principle.
Knowing the number, shape, and orientation of orbitals is critical for understanding electron configuration, hybridisation, and chemical bonding at the JEE Main level.
Orbit vs Orbital: Visual Representation
A side-by-side diagram of orbit and orbital makes the distinction clear—orbits are depicted as fixed circles around the nucleus (like planets around the sun), while orbitals show fuzzy, three-dimensional regions where electrons are most likely found.
Exam Relevance and Application of Orbit/Orbital Differences
In JEE Main, confusion between orbit and orbital can cost marks in short answer questions and MCQs on atomic structure, electron configuration, and quantum numbers. To master these concepts:
- Recall that orbits assign electron energy levels; orbitals describe probability space and electron arrangement.
- Use orbitals (s, p, d, f) when writing electronic configurations and solving quantum number questions.
- Expect direct “difference between orbit and orbital” tables or diagrams in theory-based sections.
- Apply orbitals to explain magnetic properties, hybridisation, and Pauli’s rule in chemical bonding.
- Practice translating between shell numbers (orbit) and sublevel filling (orbital) for electron arrangements.
For effective revision, always connect orbitals with their quantum numbers and geometric shapes, not just energy values.
Key Points to Remember
- An orbit is a fixed path; an orbital is a 3D region of probability.
- Only one orbital can hold 2 electrons; an orbit (shell) can accommodate more (up to 2n2).
- Orbits are part of Bohr’s model; orbitals arise from modern quantum mechanics.
- Orbitals have specific shapes—crucial for molecular bonding and structure.
- JEE Main focuses more on orbitals for electronic configuration and quantum mechanics.
Related JEE Chemistry Concepts to Explore
- Atomic Structure Mock Test
- Atomic Structure Important Questions
- Molecular Orbital Theory
- Chemical Bonding and Molecular Structure Mock Test 1
- Rules for Filling of Electron in Orbitals
- Chemical Bonding and Molecular Structure Practice Paper
- Atomic Structure Mock Test 2
- Electronic Configurations of d Block Elements
- Atomic Structure Revision Notes
- Classification of Elements and Periodicity in Properties Mock Test
- JEE Main Chemistry Syllabus
- Classification of Elements and Periodicity in Properties Practice Paper
The precise understanding of the difference between orbit and orbital is crucial for JEE Main Chemistry. Students regularly tackle theory and MCQ items on atomic structure, quantum numbers, and electron configuration. Revising this concept through comparative tables, clear definitions, and authentic practice via Vedantu helps ensure top exam performance.
FAQs on Difference Between Orbit and Orbital in Chemistry
1. What is the difference between orbit and orbital?
Orbits are fixed, circular paths around the nucleus as per Bohr’s atomic model, while orbitals are regions of high probability where electrons are likely to be found, according to quantum mechanics.
Key differences include:
- Orbits: Well-defined circular paths, described in older atomic models.
- Orbitals: 3D regions in space, defined by quantum numbers.
- Orbits: Only explain hydrogen-like atoms; limited use today.
- Orbitals: Used in modern chemistry to predict electron configuration for all atoms.
2. What is the main difference between an orbit and an orbital?
The main difference is that an orbit is a fixed, defined path for an electron, whereas an orbital is a 3-dimensional region of space where there is a high probability of finding an electron.
- Orbits: Used in Bohr's atomic model (classical concept).
- Orbitals: Used in the quantum mechanical model (modern concept).
3. What is an orbital in simple terms?
An orbital is a space or region around the nucleus where the probability of finding an electron is maximum.
- Each orbital can hold up to two electrons.
- Orbitals have different shapes, such as s (spherical) and p (dumbbell).
4. How do orbits and orbitals relate to electron arrangement in atoms?
Orbits and orbitals both describe electron arrangement, but with different models:
- Orbits place electrons in fixed, circular paths (good for basics or hydrogen atom).
- Orbitals describe complex, 3D regions where electrons are likely found (used in all modern electron configuration problems).
5. Can an electron reside in both an orbit and an orbital?
No, an electron cannot exist in both simultaneously.
- Orbits are outdated and only valid for very simple atoms (like hydrogen).
- Orbitals accurately describe electron positions in all atoms as per quantum mechanics.
6. Why was the concept of orbitals introduced after orbits?
Orbitals were introduced because the concept of orbits could not explain certain atomic behaviors (like spectra of multi-electron atoms).
- Orbits failed to match experimental data for complex atoms.
- Orbitals used quantum mechanics and probability, providing accurate predictions for electron arrangements and chemical properties.
7. What is the difference between an orbital and a subshell?
A subshell is a group of orbitals with the same energy level and shape type.
- Orbitals: Single regions where up to two electrons reside (like 1s, 2px, etc.).
- Subshells: Groups of orbitals (like s, p, d, or f) within a principal energy level.
- Example: The p subshell (like 2p) contains three orbitals: 2px, 2py, and 2pz.
8. How to represent orbitals in diagrams for exams?
Orbitals are usually shown as 3D shapes or contours representing regions of high electron probability.
- s orbitals: Drawn as spheres around the nucleus.
- p orbitals: Shown as two lobes (dumbbell-shaped) along axes (px, py, pz).
- Label orbitals clearly and indicate axes for higher marks.
9. Is “shell” the same as orbit or orbital?
No, shell, orbit, and orbital all refer to different atomic concepts.
- Shell: Principal energy level (labeled as n=1, 2, 3 or K, L, M...)
- Orbit: Specific path (now outdated, from Bohr model).
- Orbital: 3D region where an electron is likely to be found (modern, quantum mechanical concept).
10. Are all orbitals of the same shape and size?
No, orbitals differ in shape and size because they are defined by different quantum numbers.
- s orbitals: Spherical shape.
- p orbitals: Dumbbell shape.
- d and f orbitals: Complex lobed shapes.
