A physical change is a change in which the chemical composition of the substance remains the same. In other words, the substance doesn't change its identity.
Burning kerosene is a chemical change because it reacts with oxygen to produce carbon dioxide and water vapor.
Exposing white phosphorus to air is a chemical change because it reacts with oxygen to form a white powder of phosphorus pentoxide.
Dissolving calcium in water is a chemical change because it produces hydrogen gas and forms calcium hydroxide.
Freezing ice cream is a physical change because the liquid cream changes into a solid state due to the decrease in temperature, but the chemical composition of the ice cream remains the same.
Therefore, the answer is "Freezing ice cream".
