Which of the following is NOT a correct representation of the average salinity of seawater?

The average salinity of seawater is generally accepted to be around 35 parts per thousand (ppt), which translates to about 3.5% salinity. This means that for every 1,000 grams of seawater, there are approximately 35 grams of dissolved salts.

In this context, the option that states 35% salinity is incorrect because it misrepresents the actual concentration; 35% would indicate that 350 grams of salt are dissolved in 1,000 grams of seawater, which is significantly higher than the average salinity found in the oceans.

On the other hand, salinities of 30%, 40%, and 34% would also imply much higher salt concentrations than typical ocean water, but specifically, 40% is exceptionally high and not representative of average seawater conditions. Choices referencing percentages of 30% or 34% are closer to the range of salinity that can be found in some specific body of water, like estuaries or salt flats, rather than the general average of the global ocean. However, 35% explicitly misrepresents the findings about salinity, therefore making it the distinct choice that does not align with correct scientific understanding.