What forces hold iodine particles together???
Intermolecular forces called induced dipole-induced dipole attractions. I have also seen it called instantaneous dipole-induced dipole and fluctuating dipole, induced dipole. The term instantaneous dipole-induced dipole is the most descriptive, I think.
To understand the forces that hold iodine particles together, we need to explore the concept of intermolecular forces. In this context, the forces at play are specific types of intermolecular forces called induced dipole-induced dipole attractions, which can also be referred to as instantaneous dipole-induced dipole or fluctuating dipole-induced dipole forces.
These forces occur due to temporary fluctuations in electron distribution within the iodine molecule, resulting in temporary dipoles. When these temporary dipoles form, they can induce similar temporary dipoles in neighboring iodine molecules, leading to attractive forces between them.
This attraction arises because the temporary dipole in one molecule induces a complementary temporary dipole in a neighboring molecule, creating an electrostatic attraction between the opposite charges of the dipoles.
It's important to note that while iodine is composed of individual iodine molecules (I2), it is these intermolecular forces, rather than the bonds within the I2 molecule, that hold the iodine particles together in the solid state. These forces are relatively weak compared to chemical bonds but still play a crucial role in determining the physical properties of substances.