Question

The number of nodal planes in \(2 \mathrm{p}_{\mathrm{x}}\) orbital is (a) zero (b) 1 (c) 2 (d) infinite

Short answer

The number of nodal planes in a 2px orbital is (b) 1.

Step-by-step solution

Understanding Nodal Planes

Nodal planes are regions within an orbital where the probability of finding an electron is zero. For any p orbital, the nodal plane occurs where the two lobes of the p orbital intersect.

Identifying Nodal Planes in a 2px Orbital

The 2px orbital is one of the three p orbitals and it is oriented along the x-axis. It has two lobes on either side of the x-axis, with a nodal plane that passes through the nucleus and lies on the yz-plane.

Determine the Number of Nodal Planes

Since there is one plane that divides the 2px orbital into two lobes, where there is zero probability of finding an electron, there is only one nodal plane in the 2px orbital.

Key concepts

Understanding the 2px Orbital

Orbitals are often depicted as 'clouds' where electrons are likely to be found, the key to visualizing them lies in understanding their shapes and orientations. The 2px orbital is one of three p orbitals in the second principal energy level and is specifically oriented along the x-axis. This three-dimensional shape includes two bulbous lobes on either side of the nucleus.

The presence of these lobes is indicative of where an electron is most likely to be found; however, there is a region that bisects these lobes, known as a nodal plane, where the probability of finding an electron drops to zero. In the case of the 2px orbital, this nodal plane exists on the yz-plane, meaning it is perpendicular to the orientation of the lobes of the 2px orbital. Despite the complexity of orbital shapes, this particular one can be imagined akin to holding an '8' sidewise along the x axis, with the nucleus at the center.

Electron Probability in the p Orbital

The probability of finding an electron in any given location within an orbital can be described by the orbital's electron density distribution. For a p orbital, the electron density is highest at areas furthest from the nucleus, in the two lobes' extents. The pattern in which electrons are distributed represents a standing wave function with nodes, or points of zero probability, and antinodes, where probability peaks.

Within the context of the p orbital, specifically the 2px orbital, there is one nodal plane. This means that the electron probability peaks on either side of this plane, with the possibility of finding an electron being most dense in the lobes. Understanding this can provide insight not just into where an electron is likely to be found, but also how it influences molecular bonding and the spatial dynamics of molecules.

Understanding Quantum Chemistry

Quantum chemistry is a branch of chemistry focused on the application of quantum mechanics to chemical problems, helping us to understand why certain reactions occur, the bonds that form between atoms, and the properties of molecules.

At the heart of quantum chemistry lies the concept of wave functions and quantum numbers that describe the energy, shape, and orientation of electron orbitals. These ideas explain how electrons move around the nucleus and interact with each other. Nodal planes are an essential concept within quantum chemistry as they relate to the wave functions of electrons. These planes, as exhibited in the discussion of the 2px orbital, are directly related to the shape and energy states of electrons in orbitals. Understanding variables such as nodal planes can allow us to predict and manipulate the chemical behavior of substances, making quantum chemistry a crucial tool in modern scientific endeavors.