Which type of change occurs when molten gallium solidifies to Ga(s) at its normal melting point?

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

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the nature of the process described. When molten gallium solidifies to Ga(s), it changes from a liquid state to a solid state.
2. Step 2: Recall the definitions of different types of changes: Nuclear changes involve changes in the nucleus of atoms, chemical changes involve the formation or breaking of chemical bonds to form new substances, and physical changes involve changes in the state or appearance without altering the chemical identity.
3. Step 3: Since gallium remains gallium and no new substances are formed, and only the physical state changes from liquid to solid, this is not a chemical or nuclear change.
4. Step 4: Also, no electrons are transferred or involved in oxidation or reduction, so it is not a redox change.
5. Step 5: Therefore, the change occurring when molten gallium solidifies is a physical change, which involves a change in physical state without changing the chemical composition.