Answer: B. warming ice to produce water
Explanation:
A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions. Example: Melting of ice
A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.
Example: Corrosion of iron called as rusting.
Endothermic reactions are those in which heat is absorbed by the system and exothermic reactions are those in which heat is released by the system.
A. heating a rock to make it hot : It requires addition of energy and does not involve any change.
B. warming ice to produce water : It requires addition of energy and is a physical change
C. igniting a hydrogen-filled balloon: It needs energy and is a chemical change
D. burning paper to produce 
and carbon : It releases energy and is a chemical change
<u>Answer:</u> The correct option is D) 
<u>Explanation:</u>
The oxidation reaction is defined as the reaction in which a chemical species loses electrons in a chemical reaction. It occurs when oxidation number of a species increases.
A reduction reaction is defined as the reaction in which a chemical species gains electrons in a chemical reaction. It occurs when oxidation number of a species decreases.
For the given chemical reaction:
<u>On the reactant side:</u>
Oxidation number of Zn = 0
Oxidation number of Ag = +1
<u>On the product side:</u>
Oxidation number of Zn = +2
Oxidation number of Ag = 0
As the oxidation number of Ag is decreasing from +1 to 0. Thus, is getting reduced.
Hence, the correct option is D)
Answer: The Solvay process is an industrial process, also known as the ammonia-soda process
Explanation:
B. Aquaculture means "cultivating small acreages of land."
Explanation:
Aquaculture is the growing of fishes, crustaceans, molluscs, oysters and other marine organisms like algae in a small acreage of farm. Normally, the carryign capacity per acreage would be lower in the natural habitat – like in the oceans- but this is raised substantially in aquaculture due to adopting certain farming techniques. An example is by cycling the wastewater from teh fish tanks to plants that take up the waste as nutrients and oxygenate the water, The water is then recycled back to the tanks as cleaner water reusable by the fishes and teh cycle continues. This cycle ensures the sustainability of the farm even with very little water compared to the natural environment.
