When the leaf was first placed into the concentrated salt solution, it floated. later the leaf sunk. explain ?

Answer 1

Osmosis.

When you first put the leaf in the water, it's cells are filled with water with a lower salinity than the salt water you put it into. Water with a low salinity is lighter than water with a high salinity, so it floats. While the leaf sits in the water, Osmosis allows salt content in the cells to equalize with the water it's in, so the salinity raises to the point where the leaf is no longer bouyant so it sinks.

Answer 2

Osmosis is the correct answer, but to clarify it should be noted that water flows OUT of the leaf rather than salt flowing IN. When water flows out, the density of the the leaf increases until it sinks.

Answer 3

Microscopic pockets of air were trapped in the leaf. As time went on the leaf got waterlogged with the salt and the air escaped. This was due in part to the deterioration of the leaf because it was dead. The other part was because no leaf is airtight.

Answer 4

Osmosis, it absorbed salt, which is heavier than water.

Answer 5

it was water logged