What is the symbol for mercury on the period table?

Which step in naming unsaturated hydrocarbons is used for alkenes but not alkynes

Which of the following shapes would represent a molecule with two bonded atoms and 3 lone pairs on only one of them , trigonal planar , bent , trigonal pyramidal , linear

How could a student test the effect of removing heat from a gas that is stored in a sealed container? what must occur in order for matter to change states?