Chemical Equations

Kai, Lily, and Michael are conducting a chemistry experiment. They are trying to understand what reactants are in a chemical equation. Can you help them?

• Substances that they add to the chemical reaction after it has started.

• Substances present at the beginning of their chemical reaction that are used up to form products.

• Substances present at the end of their chemical reaction that are formed from products.

• Substances that are not involved in their chemical reaction.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Avery, Michael, and Ava are conducting a chemistry experiment. They mix two chemicals together and observe a reaction. What would they call the new substance that forms as a result of this reaction in the chemical equation?

• Substances formed as a result of a chemical reaction

• Substances that are not involved in a chemical reaction

• Substances that are used up in a chemical reaction

• Substances that are added to a chemical reaction after it has occurred

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Anika, Lily, and Avery were doing a science experiment. They noticed that in their balanced chemical equation, the number of atoms of each element was the same on both sides. Is this always the case? True or False?

• True

• Not always

• Sometimes

• False

Tags

NGSS.MS-PS1-5

Evelyn, Noah, and Maya are conducting a chemistry experiment. They are trying to create a chemical reaction, but they are unsure why they need to balance the chemical equation. What is the purpose of balancing a chemical equation in their experiment?

• To make the equation look more symmetrical.

• To ensure that the reactants and products they use are in the correct ratio.

• To make the equation easier for them to read.

• The purpose of balancing a chemical equation in their experiment is to obey the law of conservation of mass.

Tags

NGSS.MS-PS1-5

Grace, Anika, and Mia were conducting a chemistry experiment. They noticed that the total mass of the substances before and after the experiment remained the same. Which law does this scenario illustrate?

• It illustrates the law that mass can only be created in a chemical reaction.

• It illustrates the law of conservation of mass, which states that mass cannot be created or destroyed in a chemical reaction.

• It illustrates the law that mass can be created or destroyed in a chemical reaction.

• It illustrates the law that mass can only be destroyed in a chemical reaction.

Tags

NGSS.MS-PS1-5

Ethan, Grace, and Daniel are working on a chemistry experiment. They are trying to balance a chemical equation. What is the coefficient they should be looking for in the chemical equation?

• A coefficient in a chemical equation is a number that appears after a chemical formula.

• A coefficient in a chemical equation is a unit of measurement for the amount of a substance.

• A coefficient in a chemical equation is a symbol used to represent a specific element.

• A coefficient in a chemical equation is a number that appears in front of a chemical formula.

Tags

NGSS.MS-PS1-5

Charlotte, Olivia, and Henry are conducting a chemical experiment in their science class. They mix two substances together and observe the reaction. What happens to the mass of the substances (reactants) and the resulting compound (product) in their experiment?

• The mass of the substances and the resulting compound remains constant.

• The mass of the resulting compound increases.

• The mass of the substances decreases.

• The mass of the substances increases.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Liam, Charlotte, and Abigail are in a chemistry class. Their teacher gave them a task to balance a chemical equation. What methods could they use to balance the chemical equations?

• guessing method, reduction number method, and double-replacement method

• substitution method, reduction-oxidation method, and single-replacement method

• addition method, reduction-oxidation method, and double-replacement method

• inspection method, oxidation number method, and half-reaction method

Tags

NGSS.MS-PS1-5

James, Arjun, and Elijah are studying chemistry together. They are confused about the difference between a subscript and a coefficient in a chemical equation. Can you help them understand?

• A subscript indicates the number of atoms James, Arjun, and Elijah are using in their reaction, while a coefficient indicates the number of atoms in a compound they have.

• A subscript indicates the number of molecules or formula units in a compound that James, Arjun, and Elijah have, while a coefficient indicates the number of atoms in their reaction.

• A subscript indicates the number of molecules or formula units in a reaction that James, Arjun, and Elijah are conducting, while a coefficient indicates the number of atoms in a compound they have.

• The difference between a subscript and a coefficient in a chemical equation is that a subscript indicates the number of atoms in a compound that James, Arjun, and Elijah have, while a coefficient indicates the number of molecules or formula units in their reaction.

Tags

NGSS.MS-PS1-1

David, William, and Jackson are working on a science project where they need to balance chemical equations. What are some common mistakes they should avoid?

• Not balancing the number of atoms on each side of the equation, forgetting to include coefficients, and not considering the charges of ions in ionic compounds.

• Ignoring the conservation of mass principle

• Not accounting for the state of matter of the substances

• Using incorrect formulas for the reactants and products

Tags

NGSS.MS-PS1-5