Name a catalyst and a promoter which is used for preparing nitrogen gas. If answer is right ,, I will mark as brainillist,,so give the right answer

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

The answer is 1.82 j/g°c                  

0.50 hope this