Number 3:
Chlorine, Sodium, Sulfate, Magnesium, and Calcium.
Number 4:
The salt Increases/Decreases the density.
Hope this helps you!
:)
I’m not sure if there was important information in the question before this one, but the answer based on the info I have is B.
The density of water is 1kg/L. Since the density of the block is less, it will float.
