Identify the spectator ions in the following complete ionic equation.
ba2+(aq)+2i−(aq)+2na+(aq)+so2−4(aq) →baso4(s)+2i−(aq)+2na+(aq)

Ba2+(aq)+2I−(aq)+2Na+(aq)+SO2−4(aq)→BaSO4(s)+2I−(aq)+2Na+(aq)

The spectator ions are:    Na⁺,  I⁻.

They appear on both sides of the reaction, hence did not take part in the reaction.

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