When fresh river water meets the salty ocean the waters do a
They have different densities.
They form layers.
The fresh water floats on the salt water.
All of the above.

i believe it would be c: tons.

the alkaline earth metals (beryllium (be), magnesium (mg), calcium (ca), strontium (sr), barium (ba), and radium (ra)) are a group of chemical elements in the s-block of the periodic table with very similar properties: shiny. silvery-white. hopefully this ? i didn't fully understand the question

cell/ tissue/ organ/ organ system/ body