It is chemical because of the heat and gas which causes air bubbles
Answer:
A catalyst speeds up a chemical reaction, without being consumed by the reaction. It increases the reaction rate by lowering the activation energy for a reaction.
Explanation:

When seawater seeps down into the ocean crust and is heated by the magma, it undergoes lots of chemical reactions. When the fluid rises up through the seafloor, it carries many new chemicals with it, such as-- copper and zinc.
These chemical reactions also remove chemicals from the seawater, such as oxygen and magnesium.
So clearly vebtus fluid is different from sea water .
HOPE IT HELPS YOU.
Answer:
Cells are better seen in humid environments since 80% of their composition is water.
Explanation:
These cells have most of their composition made up of water, that is why when viewed in humid environments they maintain the micro and macrostructure of both the cell and the organelles.
This is how the structures of these cells are best perceived, it depends on their sizes if an electronic or optical microscope is used.