The closed-shell electron configuration of flerovium results in the metallic bonding in metallic flerovium being weaker than in the preceding and following elements; thus, flerovium is expected to have a low boiling point, and has recently been suggested to be possibly a gaseous metal, similar to the predictions for copernicium, which also has a closed-shell electron configuration. The melting and boiling points of flerovium were predicted in the 1970s to be around 70 °C and 150 °C, significantly lower than the values for the lighter group 14 elements (those of lead are 327 °C and 1749 °C respectively), and continuing the trend of decreasing boiling points down the group. Although earlier studies predicted a boiling point of ~1000 °C or 2840 °C, this is now considered unlikely because of the expected weak metallic bonding in flerovium and that group trends would expect flerovium to have a low sublimation enthalpy. Recent preliminary calculations predict that flerovium should have a melting point of −73 °C (lower than mercury at −39 °C and copernicium, predicted 10±11 °C) and a boiling point of 107 °C, which would make it a liquid metal. Like mercury, radon, and copernicium, but not lead and oganesson (eka-radon), flerovium is calculated to have no electron affinity.