Quiz on physical and chemical change, Characteristics of a chemical reaction

What is a chemical change?

• A change that occurs without any energy exchange

• A change where no new substances are formed

• A change that only alters the physical state

• A change that results in one or more new substances

What is the process that leads to chemical changes called?

• Chemical reaction

• Thermal reaction

• Biological reaction

• Physical reaction

What is effervescence?

• A change in color of a substance

• The release of gas bubbles in a liquid

• The formation of a solid precipitate

• The absorption of heat energy

What happens during an exothermic reaction?

• Heat energy is released

• Heat energy is absorbed

• No energy change occurs

• Only light energy is released

What is rusting an example of?

• Exothermic reaction

• Endothermic reaction

• Chemical change

• Physical change

What is formed when zinc reacts with hydrochloric acid?

• Zinc chloride

• Zinc hydroxide

• Hydrogen gas

• Zinc oxide

What characterizes a physical change?

• No new substances are formed

• Composition of the substance is altered

• New substances are formed

• Energy is always released

What is an endothermic reaction?

• A reaction that does not involve energy

• A reaction that produces light

• A reaction that releases heat

• A reaction that absorbs heat

What is the result of mixing iron powder and sulfur powder and heating them?

• Formation of iron oxide

• No reaction occurs

• Formation of sulfur dioxide

• Formation of iron sulfide

What happens to the physical state of reactants and products in many chemical reactions?

• They are always solid

• They can be different

• They always change

• They remain the same