Answer : The correct option is C.
Explanation :
Chemical change : It is defined as a change in which a new compounds are formed by the chemical reaction. Changes occurs in their chemical composition and properties.
The molecular structure of a substance changes in a chemical reaction is a chemical change.
- Change in molecular structure means that there is a breaking and formation of bonds in a molecule.
The example of chemical change in terms of change in molecular structure is the reaction of hydrogen with oxygen.
The reaction of hydrogen with oxygen is,

In this reaction, the H-H bond is break and O-H bond is form.
Buffers - mixtures of conjugate acid and conjugate base at ±1 pH unit from pH = pKa. Resistant to changes in pH in response to small additions of H+ or OH-. ... Polyprotic acids - dissociation of each H+ can be treated separately if the pKa values are different
Hey there!
Label A: Sublimation
Label B: Condensation
Label C: Melting
Remember sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state. Condensation is the conversion of a vapor or gas to a liquid. Melting is becoming liquefied by heat.
Hope this helps!