Question

The shape of the orbital is determined by a quantum number which is represented by the symbol
A.$l$
B.$n$
C.$m$
D.$s$

Answer 1

To answer this question, you should recall the concept of quantum number. Quantum numbers can be used to describe the trajectory and the movement of an electron in an atom. The quantum numbers of all the electrons in a given atom, when combined, must comply with the Schrodinger equation.

Complete Step by step solution:
The set of numbers used to describe the position and energy of the electron in an atom are called quantum numbers. You should know that four quantum numbers can be used to completely describe all the attributes of a given electron belonging to an atom, these are:
Principal quantum number, denoted by $n$;
Orbital angular momentum quantum number (or azimuthal quantum number), denoted by $\;l$;
Magnetic quantum number, denoted by ${m_l}$;
The electron spin quantum number, denoted by ${m_s}$.

Hence, the correct option is option A.

Note: For determining the position of ray electron you should know about Heisenberg’s uncertainty principle. To understand Heisenberg’s uncertainty principle in a better way, consider an example where the position of an electron is measured. Now to measure the position of an object, we need light, so a photon must collide with it and return to the measuring device. We know that photons hold some finite momentum, a transfer of momenta will occur when the photon collides with the electron. This transfer of momenta from photon to electron will cause the momentum of the electron to change. This would mean that an attempt at measuring the position of a particle will cause uncertainty in the value of its momentum. Heisenberg’s uncertainty principle has a negligible impact on macroscopic objects as the mass of a ball is much larger than that of an electron.