6. Is mercury a heavier element than tin?

How many moles is 14.5 cm^3 of platinum? the density of platinum is 21.45 g/cm^3.

4.25g sample of solid ammonium nitrate dissolves in 60.0g of water in a coffee-cup calorimeter, the temperature drops from 22.0 c to 16.9 c. assume that the specific heat of the solution is the same as that of pure water. calculate delta(h) (in kj/mol nh4no3) for the solution proces.

Select the correct lewis structure for fluorine which is group 7a element?