It is true that plants need salts and minerals to grow, but access salts can lead to the plant dying. (Like how humans need some salt in there diet, but access salt is not healthy. That is why it is bad to drink sea water) Anna's way of thinking is incorrect. Salty water could lead to the plant dying because too much salt could be toxic instead of helping them grow better.
The force that acts on the particles of a liquid of a surface is called 'Surface Tension'.
