Which of the Following Directly Determine the Physical State of a Substance

Question

Which of the following directly determine the physical state of a substance at a given temperature?
A) covalent bonds
B) intermolecular forces
C) intramolecular forces
D) nuclear forces

Accepted Answer

The physical state of a substance at a given temperature is determined by the balance between the kinetic energy of the particles (which tends to increase the distance between them) and the strength of the intermolecular forces (which tends to keep them close together). If the intermolecular forces are weak, the substance will be in a gaseous state at that temperature, if they are moderately strong, the substance will be in a liquid state, and if they are very strong, the substance will be in a solid state. Covalent bonds and intramolecular forces are strong forces that hold molecules together, but they do not directly determine the physical state of a substance. Nuclear forces are even stronger, but their effects are only evident at the atomic and subatomic level.