Question

Ice is slippery when it isn't too far below it's melting point because the surface molecules are less loosely bound than the bulk and form athin liquid layer. Pressure melting is a much smaller effect since it takes about10 MPaof pressure per degree below freezing, which is more than ice skates can apply. Presumably this "edge effect" isn't unique to water. Gallium at 20C (melting point about 30C) should also have such a surface layer. But most metals oxidize if exposed to air and/or water, forming an oxide layer which (in this case) melts at much higher temperatures. But if gallium at 20C is placed in argon and the oxide layer is removed, would the underlying metal feel slippery to a gloved hand?

Answer 1

If gallium at 20°C has its oxide layer removed and is placed in an inert atmosphere, it might exhibit a slippery surface due to a quasi-liquid layer, similar to the phenomenon seen with ice.

Step-by-step explanation:

The phenomenon of ice being slippery is attributed to the formation of a thin liquid layer on the surface, which occurs due to the lesser binding of surface molecules compared to those in the bulk. This effect is not limited to water; other substances may exhibit similar behavior under analogous conditions.

For instance, gallium has a melting point of about 30°C, and at 20°C, sufficiently free of oxide layer and placed in an inert atmosphere like argon, might also present a slippery surface due to the presence of a quasi-liquid layer on its surface. Thus, the underlying metal could feel slippery if the oxide layer is removed and the metal is under conditions preventing reoxidation.