The storage method used for radioactive wastes generated from fission nuclear reactors must be designed to last for hov
long?
months
years
centuries
weeks
arch

Silicon nitride is difficult to produce as a bulk material it can't be heated over 1850 °C, which is  below its melting point, due to dissociation to silicon and nitrogen.

Explanation:

Silicon crystallises in a giant covalent structure at standard conditions, specifically in a diamond cubic lattice. It thus has a high melting point of 1414 °C. It is not known to have any allotropes at standard pressure, but several other crystal structures are known at higher pressures.