The video tutorial explains chemical reactions as processes where substances interact to form new substances by altering chemical bonds. It uses photosynthesis as an example, detailing how plants convert carbon dioxide and water into glucose and oxygen. The tutorial covers writing chemical equations, emphasizing the need for balance due to the law of conservation of matter. It explains that reactants and products must contain the same elements and number of atoms. The video concludes with a review of key concepts, including the roles of reactants and products, and the importance of balanced chemical equations.

What is a chemical reaction?

• A process where substances are separated into their individual elements

• A process where substances are physically combined

• A process where substances interact to form new substances by changing their chemical bonds

• A process where substances are mixed without changing their chemical bonds

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In the process of photosynthesis, what are the reactants?

• Glucose and oxygen

• Carbon dioxide and water

• Sunlight and oxygen

• Glucose and water

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What are the products of the photosynthesis reaction?

• Carbon dioxide and water

• Glucose and oxygen

• Water and glucose

• Sunlight and carbon dioxide

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How do scientists represent a chemical reaction?

• With a physical model

• With a chemical equation

• With a diagram

• With a written description

In a chemical equation, where are the reactants and products placed?

• Reactants on the left, products on the right

• Reactants above, products below

• Reactants on the right, products on the left

• Reactants and products on the same side

Why must a chemical equation be balanced?

• To ensure the reaction occurs

• To follow the law of conservation of matter

• To make it easier to read

• To show the energy change in the reaction

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What does the law of conservation of matter state?

• Matter can be created and destroyed

• Matter can only change forms, not be created or destroyed

• Matter is always conserved in physical changes

• Matter can be converted into energy

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What are coefficients in a chemical equation?

• Numbers that represent the speed of the reaction

• Numbers that indicate the number of molecules of each reactant and product

• Numbers that indicate the amount of energy in the reaction

• Numbers that show the temperature of the reaction

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What happens to chemical bonds during a chemical reaction?

• They remain unchanged

• They are broken and reformed to create new substances

• They are only broken

• They are only reformed

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What must be equal in a balanced chemical equation?

• The number of molecules of each substance

• The number of atoms of each element in the reactants and products

• The mass of the reactants and products

• The volume of the reactants and products

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