What happens to the molecules during a chemical change? a) They remain the same move faster but remain unchanged (C) They are rearranged to form a new substance d) They change state from solid to liquid Which of these is a physical property of copper? a) It reacts with oxygen to form a green pating b) It conducts electricity C) If burns in air (d) It reacts with acids A chemical property can be observed when a substance: a) Changes its color b) Melts into a liquid (C) Forms a new substance d) Breaks into pieces Which of the following changes is not a physical change? a) Cutting wood b) Melting butter c) Burning paper d) Freezing water What property describes a substance's ability to dissolve in water? a) Solubility b) Reactivity C)Density d) Flammability Which of these is not a physical property? a)Shape b) Ability to rust c) Density d) Volume Which of the following best represents a chemical change? b) Water evaporating c) Food rotting d) Sugar dissolving in tea

Here are the answers and explanations for the questions:**1. What happens to the molecules during a chemical change?*** **(C) They are rearranged to form a new substance** Chemical changes involve the breaking and forming of new chemical bonds, resulting in the creation of entirely different molecules with different properties.**2. Which of these is a physical property of copper?*** **(b) It conducts electricity** Physical properties are characteristics that can be observed without changing the substance's chemical composition. Copper's ability to conduct electricity is a physical property.**3. A chemical property can be observed when a substance:*** **(C) Forms a new substance** Chemical properties describe how a substance reacts with other substances or under specific conditions, leading to the formation of new substances.**4. Which of the following changes is not a physical change?*** **(c) Burning paper** Burning paper is a chemical change because it involves combustion, a chemical reaction that produces ash, carbon dioxide, and other products.**5. What property describes a substance's ability to dissolve in water?*** **(a) Solubility** Solubility refers to the ability of a substance to dissolve in a solvent, such as water.**6. Which of these is not a physical property?*** **(b) Ability to rust** Rusting is a chemical change (oxidation) that alters the composition of the substance.**7. Which of the following best represents a chemical change?*** **(c) Food rotting** Food rotting involves complex chemical reactions that break down the food's molecules, resulting in a change in its composition and appearance.