Chemical change happens when a substance combines with
another substance to form a new substance. It produces chemical reactions and
generally is not reversible except by further chemical reactions. Heat is sometimes
produced in some reactions. When chemical reactions occur, the atoms are
rearranged and an energy change happens along with it as new products are
generations. At a molecular level, chemical changes involves the making or
breaking of bonds between atoms. Some examples of chemical change are iron
rusting (iron oxide forms) and bread rising (yeast converts carbohydrates into
carbon dioxide gas).
Answer:
positive
positive
Explanation:
Entropy -
In a system, the randomness is measured by the term entropy .
Randomness basically refers as a form of energy that can not be used for any work.
The change in entropy is given by amount heat per change in temperature.
- When solid is converted to gas entropy increases,
As the molecules in solid state are tightly packed and has more force of attraction between the molecules, but as it is converted to gas, the force of attraction between the molecule decreases and hence entropy increases.
So,
The particles of the substance , if are tightly held by strong force of attraction will decrease the entropy ,
And
If the particles are loosely held , the entropy will increase , i.e. , positive entropy .
Similar with solid converting to liquid , the entropy will increases , i.e. , positive entropy .
Hence ,
The correct sign of entropy for both the process is positive .
Answer:
hydrogen bonds, the positive and negative charges of the hydrogen and oxygen atoms that make up water molecules makes them attracted to one another.
