Aclosed container is filled with oxygen. the pressure in the container is 225 kpa . what is the pressure in millimeters of mercury?

That kilo-pascal is equivalent to 1678. 64 millimeters of mercury  pressure

The density of water is 1 g/cm cubed and in order for the pebble to sink its density has to be greater than the density of water and in order for the twig to float its density has to be less than the density of water

Answer; carbon monoxide (co);