An angiogram uses X-rays and a special dye (contrast) to take pictures of the arteries in your brain, heart, and kidneys. The dye is injected into a small tube or catheter into an artery in your groin or (sometimes) your arm.
As the cloud collapses the force of gravity drawing the cloud inward gradually becomes stronger because the strength of gravity follows an inverse square law with distance. hoâ¦pe that helps.
Van der Waals force. Van der Waals forces include attraction and repulsions between atoms, molecules, and surfaces, as well as other intermolecular forces. They differ from covalent and ionic bonding in that they are caused by correlations in the fluctuating polarizations of nearby particles (a consequence of quantum dynamics[5]).