The atoms of a solid are strongly attracted to each other. Solids keep their shape because of these strong attractions. The atoms vibrate but do not move past each other.

because helium atoms are lighter than the atoms in air. So a helium balloon floats! Water has a higher density than air. The particles in a solid are tightly packed, so a lot of particles fit into ...

"[But] this type of touching does not really make sense at the atomic scale because atoms do not have well-defined outer surfaces." An atom is neither a solid object nor the smallest unit known to ...

ACCORDING to the theory of specific heats developed by Debye, Nernst, and others, the thermal energy of a solid is made up of the energy of elastic vibrations in its material, the frequencies of ...