What does a molecule having dipole moment signify?

AI Thread Summary
A dipole moment in a molecule signifies the separation of positive and negative charges, indicating how asymmetrical the charge distribution is. A large dipole moment occurs when one end of the molecule has excess positive charge and the other end has excess negative charge, often due to differences in electronegativity. Molecules with equal positive charges on both ends will have no net dipole moment, as the charges cancel each other out. Additionally, all atoms and molecules possess magnetic moments, with electrons, protons, and neutrons contributing to these moments, although they can pair up to cancel each other. Understanding dipole moments is crucial for grasping molecular interactions and behaviors in various chemical contexts.
Idoubt
Messages
170
Reaction score
1
Can someone give me a clear picture of it's physical meaning? What does a molecule having dipole moment signify? All the explanations I've seen are very hazy.
 
Physics news on Phys.org
Basically you can think of the dipole moment as representing how off-center the positive charge in an object is compared to the negative charge. So if you have a molecule with some extra positive charge on one end and some extra negative charge on the other end, it will have a large dipole moment. (That would happen if the latter end attracts the molecule's electrons more than the former end) If a molecule had some extra positive charge on one end but also had the same amount of extra positive charge on the other end, they would cancel out and not contribute to any net dipole moment.
 
Most atoms and molecules have magnetic (dipole) moments. The electron has an intrinsic magnetic dipole moment related to "spin" (measured in Bohr magnetons), and electron orbitals have orbital magnetic dipole moments dependent on the l (lower case L) quantum number. Protons and neutrons have intrinsic dipole moments (measured in nuclear magnetons). Nuclei also have magnetic moments. However protons, neutrons, and electrons sometimes pair up so as to cancel magnetic moments. Helium in its ground state (2 protons, 2 neutrons, and 2 electrons in the 1S ground state) has no magnetic dipole moment. (Same for alpha particles.) The electron orbital dipole moment for l>=1 (L>=1) can be thought of as a current loop, although the analogy is not rigorous.
 
Thread 'Gauss' law seems to imply instantaneous electric field propagation'

Thread 'Gauss' law seems to imply instantaneous electric field propagation'

Imagine a charged sphere at the origin connected through an open switch to a vertical grounded wire. We wish to find an expression for the horizontal component of the electric field at a distance ##\mathbf{r}## from the sphere as it discharges. By using the Lorenz gauge condition: $$\nabla \cdot \mathbf{A} + \frac{1}{c^2}\frac{\partial \phi}{\partial t}=0\tag{1}$$ we find the following retarded solutions to the Maxwell equations If we assume that...
View full post »

Thread 'Do electron density waves accompany EM waves in coaxial cables?'

Maxwell’s equations imply the following wave equation for the electric field $$\nabla^2\mathbf{E}-\frac{1}{c^2}\frac{\partial^2\mathbf{E}}{\partial t^2} = \frac{1}{\varepsilon_0}\nabla\rho+\mu_0\frac{\partial\mathbf J}{\partial t}.\tag{1}$$ I wonder if eqn.##(1)## can be split into the following transverse part $$\nabla^2\mathbf{E}_T-\frac{1}{c^2}\frac{\partial^2\mathbf{E}_T}{\partial t^2} = \mu_0\frac{\partial\mathbf{J}_T}{\partial t}\tag{2}$$ and longitudinal part...
View full post »
Thread 'Recovering Hamilton's Equations from Poisson brackets'

Thread 'Recovering Hamilton's Equations from Poisson brackets'

The issue : Let me start by copying and pasting the relevant passage from the text, thanks to modern day methods of computing. The trouble is, in equation (4.79), it completely ignores the partial derivative of ##q_i## with respect to time, i.e. it puts ##\partial q_i/\partial t=0##. But ##q_i## is a dynamical variable of ##t##, or ##q_i(t)##. In the derivation of Hamilton's equations from the Hamiltonian, viz. ##H = p_i \dot q_i-L##, nowhere did we assume that ##\partial q_i/\partial...
View full post »

Similar threads

B Direction of Electric Field & Field Due to a Dipole
Replies
5
Views
3K
I Exact electrostatic potential of a pure dipole using multipole expansion
Replies
6
Views
2K
A Mass measurement in a Penning trap
Replies
0
Views
800
I Instantaneous dipole moment and orbitals
Replies
2
Views
168
I What is the significance of dipole moments in physics?
Replies
1
Views
852
I What Exactly is the Anapole Moment?
Replies
3
Views
3K
I Question regarding how to interpret dipole moment for bound charges
Replies
1
Views
2K
I Dipole moment of a cylinder of uniform polarization
Replies
10
Views
2K
Why is a current ring approx a magnetic dipole from very far off?
Replies
7
Views
2K
A Induced dipole moment (adiabatic) following the rotating E-field
Replies
4
Views
1K

Hot Threads

Recent Insights

Back
Top