Under normal conditions, most of the elements exist in the solid phase. Some, however, exist as gases
or liquids. The internal structure and the element's intermolecular forces govern the state of the element
at a given temperature.
Changing the temperature alters the ability of the particles of the bulk element to overcome the forces holding
them together, possibly causing the element to solidify, melt or vaporize. In these cases, the phase of a
substance is governed by competing forces. Intermolecular (or interatomic forces) arrange the substance as a liquid
or solid, while thermal motions attempt to separate the particles into the gas phase. As the temperature
rises, the thermal motions of a solid substance overcome the intermolecular or interatomic forces, converting it
first to a liquid and finally to a gas. Melting points and boiling points of the elements give an indication
of their relative intermolecular or interatomic forces.
This program demonstrates the effect of temperature on the phases of the elements. As the temperature is
varied, the computer generated periodic table changes color to indicate the state of each element. The phase
of each element will be denoted by the color of its box.
INSTRUCTIONS