People, who are new to atomic theory, generally find the terms ‘Orbit’ and ‘Orbital’ the same. However, this is not the case. Both of these terms are very different from one another in multiple aspects.
Orbit vs Orbital
The main difference between Orbit and Orbital is that an orbit is considered to be a definite path on which electrons revolve, whereas an Orbital is an area that is uncertain, and the chances of finding an electron here are maximum. Orbit is a two dimensional or a planar area. However, an orbital represents a three-dimensional area where the probability of finding an electron is maximum.
You can think of electrons in an atom as planets of our solar system, where the nucleus represents the sun. These electrons tend to revolve on a path that is called an orbit. While electrons revolve around their orbit, they use to follow every principle that a planet follows while revolving around the sun.
According to Heisenberg’s uncertainty principle, the
position of an electron can’t be determined accurately. To represent the
position of the electron inside of an atom, the concept of the orbital is
introduced.
However, orbital also doesn’t state the speed, direction,
and position of an electron. But it gives an accurate idea of where an electron
might be.
Comparison Table Between Orbit and Orbital (in Tabular Form)
| Parameter of Comparison | Orbit | Orbital |
|---|---|---|
| Definition | A path on which electrons revolve around the nucleus of an atom is called Orbit. | The three-dimensional space in which the chances of finding an electron is quite high is known as Orbital. |
| Accuracy in Position | It represents the exact position of an electron inside of an atom. | It cannot represent the accurate position of an electron. |
| Uncertainty Principle | An Orbit doesn’t follow the Heisenberg’s Uncertainty Principle as it claims to state the exact position of an electron. | As an orbital does not represent the exact position of an electron, it follows the Heisenberg’s Uncertainty Principle. |
| Shape | Every orbit possesses a circular shape. | An orbital has different forms of it – spherical, bell-shaped, etc. |
| Designation | Orbits are defined by the letters K, L, M, N, etc. | Orbital is mainly defined by using the letters s, p, d, and f. |
What is Orbit?
An orbit is defined as a definite path that is circular in shape, on which electrons revolve due to the pull experienced by the electron towards the positively charged nucleus. This is what Bohr’s atomic theory states.
The Bohr’s model also states that the first shell of an atom
will hold only 2 electrons. However, Bohr’s model was, later on, got rejected.
The widely accepted model in the present time is the one that
states the concept of the orbital. In order to understand the concept of an
orbit, you need to know about the solar system.
Think of it in this way, the planets in the solar system represent the electrons, which are revolving around the sun, which is a nucleus in this case.
Like the planets, the electrons also do follow Newton’s laws of motion while revolving around the nucleus. Unlike an orbital, an orbit is only a two-dimensional path. A single orbit can hold up to 2n2 number of electrons.
According to Heisenberg’s uncertainty principle, the accurate position of an electron is something that cannot be determined.
This is where the concept of orbital comes in.
What is Orbital?
The exact position of an electron cannot be determined, as
stated in the principle of Heisenberg. This is what introduces us to the
orbital.
An orbital is an uncertain area that depicts the maximum
possibility of finding an electron there. The three-dimensional space around
the nucleus represents the orbital.
Orbital possesses various kinds of shapes. Orbitals are generally categorized into four forms – s, p, d, and f. The s orbital has a maximum capacity of holding 2 electrons, p can hold up to 6, d can hold 10, whereas f can hold 16 numbers of electrons.
In the three-dimensional region of the atom, the probability
of finding an electron is quite high, to say, 95 percent.
In orbitals, it is quite easy to determine the shape of
molecules as they are directional. The orbital highly relies on the principle
of Heisenberg.
Main Differences Between Orbit and Orbital
- An orbit is a path that is definite on which an electron revolves. However, an orbital is a three-dimensional path where the possibility of finding an electron is quite high.
- An orbit claims to depict the exact position of an electron within an atom, whereas an orbital does not claim to describe the accurate position of electrons.
- A two dimensional or planar motion of electrons is found in orbit. However, electrons move in a three-dimensional space around the nucleus in an orbital.
- As Orbits claim to tell the accurate position of electrons, it does not go well with the Heisenberg’s Uncertainty Principle.
An orbital does not specify the position of an electron, and it might be anywhere in that 3d space. Therefore, it goes well with the principle of Heisenberg. - None of the orbits shows any characteristics that include direction, whereas in the case of orbital, directional characteristics can be seen, except for s orbital.
Conclusion
Orbit and Orbital are two different terms, and both of them are related to an atom. The concept of the orbit in an atom is exactly the same as that of planets revolving around the sun in the solar system.
The electrons in orbit completely follow Newton’s laws of
motion. However, they do not align with Heisenberg’s Uncertainty Principle.
An Orbital represents the 3D space around the nucleus in which the probability of finding an electron is quite high. It completely follows the Heisenberg’s Uncertainty Principle.
According to Heisenberg’s Uncertainty Principle, there is no possible way to accurately determine the movement, speed, and direction of an electron within an atom.
The only thing you can get is a rough representation of where you might find an electron within the atom.
References
- https://www.birpublications.org/doi/pdf/10.1038/sj/dmfr/4600551
- https://www.oto.theclinics.com/article/S0030-6665(11)00102-2/abstract