Answer : The correct option is, (C) metal corroding in salt water.
Explanation :
Chemical change : It is a change where changes occurs in the chemical composition and thus resulting in the formation of new compound or substance. It is an irreversible reaction.
The indication of chemical changes are :
Formation of gas bubbles.
Formation of precipitate.
Change in color.
Change in temperature.
Change in volume.
Change in smell or taste.
Evolution of heat, light and sound.
Physical change : It is a change in which shape and size of a substance changes. In this there is no change in the chemical composition of the substance and no new substance is forming. It is a reversible reaction.
The indication of chemical changes are :
Change in shape.
Change in form.
Change in size.
Change in phase.
(A) Mixing of poster colors : It is a physical change because only changes takes place in the phase from liquid phase to vapor phase.
(B) Formation of clouds : It is a physical change because only changes takes place in the phase from vapor phase to liquid phase.
(C) Metal corroding in salt water : It is a chemical change because the chemical composition of substance changes.
(D) Sugar dissolving in water : It is a physical change because only changes takes place in the phase from solid phase to liquid phase.
(E) Separating salt from seawater : It is a physical change because only changes takes place in the phase from liquid phase to solid phase.
Hence, the correct option is, (C) metal corroding in salt water.
