Researchers at SLAC National Accelerator Lab have developed a new electron-gun that produces near-continuous high-energy electron beams. The electron gun uses a chamber of niobium cooled to 4 kelvins, which has what property?

W) Piezoelectricity [PEE-zoh-electricity]

X) Extremely high magnetic susceptibility

Y) Superfluidity

Z) Superconductivity
Z) SUPERCONDUCTIVITY