Question

1. what are sources of dissolved substances in seawater? 2. how does salinity affect the density of seawater?

Explanation:

1. Weathering of rocks on land, volcanic eruptions, hydrothermal vents at mid - ocean ridges, and decomposition of marine organisms are sources of dissolved substances in seawater.
2. As salinity increases, the density of seawater increases. This is because dissolved salts add mass to the water without significantly increasing its volume.

Answer:

1. Weathering of rocks, volcanic eruptions, hydrothermal vents, decomposition of marine organisms.
2. As salinity increases, seawater density increases.