A free-floating photosynthetic autotroph that lives in freshwater or saltwater
A free-floating photosynthetic autotroph that lives in freshwater or saltwater

A free-floating photosynthetic autotroph that lives in freshwater or saltwater
Atoms of the same element that differ in the number of neutrons
The center of an atom
Particles with no charge
A pH greater than 7
An ecosystem that is formed where freshwater from a river or stream merges with salt water from the ocean.
A body of water that’s shallow enough for sunlight to penetrate.
On the left side of the arrow
How is the abyssal part of the ocean where little or no sunlight can penetrate otherwise described?
Is a chart that shows columns (families) and rows (periods) of elements