143. Solving a chemistry problem

4.18. Determine how the total surface of all particles contained in a metal Ni powder with an average size of 0.1 μm changes when dispersed to 100 nm, which becomes pyrophoric, i.e., ignites when it comes into contact with air. Calculate the flash point (melting point) of nickel dispersed to 100 nm. The melting point of compact nickel is 1453 ° C. Heat of fusion 303 kJ / kg.