How do surface currents differ from deep ocean currents? Deepwater currents are dependent on the wind and landmasses. Deepwater currents are dependent on temperature and salinity. Deep ocean currents are affected by salinity and wind. None of the above​

surface currents are caused by winds : deep water currents are caused by difference in water density.

I guess the answer of your question is this

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.