Arsenic sublimates because it has a low melting point and a high vapor pressure. This means that at room temperature, the atoms of arsenic have enough energy to break free from the solid form and transition directly into a gas without passing through a liquid state.
Gallium melts because it has a higher melting point compared to arsenic. This means that at room temperature, the atoms of gallium do not have enough energy to transition directly from solid to gas, and instead must pass through a liquid state.
The melting and sublimation of elements are affected by various factors such as the strength of intermolecular forces, atomic size, and atomic structure. Elements with stronger intermolecular forces and larger atomic size will have higher melting points and are less likely to sublimate.
Yes, both arsenic and gallium can exist in a gaseous state. However, the conditions for their sublimation and melting are different due to the differences in their physical properties.
Gallium is often referred to as a "metal with a low melting point" because it has one of the lowest melting points among all metals. Its melting point is only 29.76°C, which makes it one of the few elements that are liquid at room temperature.