Final Answer:
Dissolved ions are chemically soluble and transported within a river, while suspended particles like clay and silt remain indefinitely above the riverbed. The bed of a river comprises materials such as sand and gravel, moved along its bottom through pushing, bouncing, rolling, and sliding.
Explanation:
Dissolved substances in a river refer to ions that chemically dissolve and become part of the water, being transported within the river's flow. These dissolved ions, like minerals and salts, aren't visible and are integrated into the water molecules themselves. Suspended particles like clay and silt remain above the riverbed due to their lighter weight, carried along with the water's current without settling down. They're visible within the water as cloudy or murky suspensions but don't fully mix or dissolve.
The bed of a river constitutes the materials transported along its bottom, predominantly consisting of sand and gravel. These sediments move through various processes like pushing, bouncing, rolling, and sliding due to the force of the water flow, constantly shaping and altering the river's structure.
Rivers serve as complex systems where dissolved substances, suspended particles, and bed materials interact differently, influencing the water's composition, turbidity, and bottom structure. Understanding these distinctions helps in assessing water quality, erosion patterns, and ecological impacts within river ecosystems.