It's a physical change. A physical change is when an object can return back to it's previous state, etc. If it was a chemical change, the object would not be able to return back to it's previous shape, state or size, etc.
Bonds formed between atoms can be classified as ionic and covalent
Ionic bonds are formed between atoms that have a high difference in the electronegativity values.
In contrast, bonds formed between atoms that have a difference in electronegativity lower than the ionic counterparts are polar covalent bonds. If the atoms have very similar electronegativities, they form non-polar covalent bonds.
In H2S, the S atom is bonded to 2 H atoms. The electronegativity of H = 2.2 and S= 2.56. Since the difference is not high the bond formed will be covalent (polar covalent).
B. Dissolved Oxygen
is a measure of the oxygen in a body of water.
The correct answer for this question is this one: "<span>In transpiration, because some of its properties change, water undergoes a physical change but keeps its identity. In photosynthesis, because its identity changes, water undergoes a chemical change</span>. "
Hope this helps answer your question and have a nice day ahead.