what is this bad conductor?
It is a chemical element with the symbol Hg and atomic number 80
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. 
mercury is good or bad conductor of heat Bad conductor of heat
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Mercury (element) [SEP] Introduction
Mercury is a chemical element with the symbol Hg and atomic number 80. It is commonly known as quicksilver and was formerly named hydrargyrum ( ). A heavy, silvery d-block element, mercury is the only metallic element that is liquid at standard conditions for temperature and pressure; the only other element that is liquid under these conditions is the halogen bromine, though metals such as caesium, gallium, and rubidium melt just above room temperature. Mercury occurs in deposits throughout the world mostly as cinnabar (mercuric sulfide). The red pigment vermilion is obtained by grinding natural cinnabar or synthetic mercuric sulfide.