Chemical Equations

What are reactants in a chemical equation?

• Substances that are produced in a chemical reaction.

• Starting substances that undergo a chemical change.

• Elements that do not participate in the reaction.

• Byproducts of a chemical reaction.

What is the Law of Conservation of Mass?

• The mass of the products in a chemical reaction must equal the mass of the reactants.

• Mass can be created or destroyed in a chemical reaction.

• The total mass of a closed system remains constant over time.

• The mass of reactants is always greater than the mass of products.

What does it mean to balance a chemical equation?

• It means to ensure that the number of atoms for each element is the same on both sides of the equation.

• It means to add more reactants to increase the reaction rate.

• It means to change the state of matter of the reactants.

• It means to increase the temperature of the reaction.

Which one is a compound?

• CO (Carbon Monoxide)

• O2 (Oxygen)

• N2 (Nitrogen)

• H2 (Hydrogen)

What is a subscript in a chemical formula?

• A subscript indicates the number of atoms of the element in a molecule.

• A subscript represents the charge of the element in a molecule.

• A subscript shows the state of matter of the element in a molecule.

• A subscript denotes the type of bond between elements in a molecule.

How many atoms of carbon (C) are in C₆H₁₂O₆?

• 4

• 5

• 6

• 7

What is a molecule?

• A molecule is a single atom.

• A molecule is a group of two or more atoms bonded together.

• A molecule is a type of chemical reaction.

• A molecule is a form of energy.

What is the purpose of a chemical equation?

• To provide a concise way to describe a chemical reaction and the substances involved.

• To list all the elements in the periodic table.

• To explain the history of chemistry.

• To predict the weather based on chemical reactions.

What is the Law of Conservation of Matter?

• Matter can be created and destroyed.

• Matter cannot be created or destroyed; it only rearranges.

• Matter can change forms but not quantity.

• Matter is only conserved in closed systems.

How many Oxygen (O) are in 2H₂O?

• 1

• 2

• 3

• 4