Which type of change occurs when water (H_2O) freezes into ice?

• A. Physical change
• B. Chemical change
• C. Electrochemical change
• D. Nuclear change

Answer: (A)

Verified step by step guidance

1. Understand the difference between physical and chemical changes: A physical change affects the form or state of a substance without altering its chemical composition, while a chemical change results in the formation of new substances with different chemical properties.
2. Identify what happens when water freezes: Water changes from liquid to solid (ice), which is a change in its physical state.
3. Recognize that during freezing, the molecular structure of H_2O remains the same; only the arrangement and energy of the molecules change.
4. Conclude that since the chemical identity of water does not change during freezing, this process is a physical change.
5. Note that electrochemical and nuclear changes involve electron transfer or changes in the nucleus, respectively, which do not occur in the freezing of water.