Question

Which of the following is a physical change:

a.wood burning in a fireplace
b.water freezing
c.iron rusting
d.milk souring

Answer 1

b.Water freezing is a physical change because it involves a change of state without altering the chemical composition of the substance.

Step-by-step explanation:

The question refers to differentiating between physical and chemical changes. Among the given options, water freezing is a physical change. When water freezes, it changes from a liquid to a solid state, but the composition of water doesn't change - it remains H2O.

This process is reversible; if the ice melts, it turns back into liquid water. In contrast, burning wood, iron rusting, and milk souring are all chemical changes because they result in the formation of new substances with different chemical properties that are not easily reversible.