Foil (metal)
A foil is a very thin sheet of metal, usually made by hammering or rolling. Foils are most easily made with malleable metals, such as aluminium, copper, tin, and gold. Foils usually bend under their own weight and can be torn easily. The more malleable a metal, the thinner foil can be made with it. For example, aluminium foil is usually about 1/1000 inch (0.03 mm), whereas gold (more malleable than aluminium) can be made into foil only a few atoms thick, called gold leaf. Extremely thin foil is called metal leaf. Leaf tears very easily and must be picked up with special brushes.
Flerovium
In a 2014 paper detailing the experimental results of the chemical characterisation of flerovium, the GSI group wrote: "[flerovium] is the least reactive element in the group, but still a metal." Nevertheless, in a 2016 conference about the chemistry and physics of heavy and superheavy elements, Alexander Yakushev and Robert Eichler, two scientists who had been active at GSI and FLNR in determining the chemistry of flerovium, still urged caution based on the inconsistencies of the various experiments previously listed, noting that the question of whether flerovium was a metal or a noble gas was still open with the available evidence: one study suggested a weak noble-gas-like interaction between flerovium and gold, while the other suggested a stronger metallic interaction. The same year, new experiments aimed at probing the chemistry of copernicium and flerovium were conducted at GSI's TASCA facility, and the data from these experiments is currently being analysed. As such, unambiguous determination of the chemical characteristics of flerovium has yet to have been established, although the experiments to date have allowed the first experimental estimation of flerovium's boiling point: around −60 °C, so that it is probably a gas at standard conditions. The longer-lived flerovium isotope Fl has been considered of interest for future radiochemical studies.