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Balancing Equations

The law of conservation of mass and balancing equations are the focus of this segment with students performing a lab to explore these topics.

Chemical reactions are the focus of this segment. The students perform a lab to write and balance chemical equations.

Premiere Date: July 11, 2016 | Runtime: 00:15:31

Support Materials


Measuring Chemical Reactions
Unit 5A Note Taking Guide & Segment Questions

Crosscutting Concepts

System and System Models

Defining the system under study—specifying its boundaries and making explicit a model of that system—provides tools for understanding and testing ideas that are applicable throughout science and engineering.


Observed patterns of forms and events guide organization and classification, and they prompt questions about relationships and the factors that influence them.

Energy and Matter

Flows, cycles, and conservation. Tracking fluxes of energy and matter into, out of, and within systems helps one understand the systems’ possibilities and limitations.

Stability and Change

For natural and built systems alike, conditions of stability and determinants of rates of change or evolution of a system are critical elements of study.

Science & Engineering Practices

Analyzing and Interpreting Data

Once collected, data must be presented in a form that can reveal any patterns and relationships and that allows results to be communicated to others. Because raw data as such have little meaning, a major practice of scientists is to organize and interpret data through tabulating, graphing, or statistical analysis. Such analysis can bring out the meaning of data—and their relevance—so that they may be used as evidence.
Engineers, too, make decisions based on evidence that a given design will work; they rarely rely on trial and error. Engineers often analyze a design by creating a model or prototype and collecting extensive data on how it performs, including under extreme conditions. Analysis of this kind of data not only informs design decisions and enables the prediction or assessment of performance but also helps define or clarify problems, determine economic feasibility, evaluate alternatives, and investigate failures. (NRC Framework, 2012, p. 61-62)

Engaging in Argument from Evidence

The study of science and engineering should produce a sense of the process of argument necessary for advancing and defending a new idea or an explanation of a phenomenon and the norms for conducting such arguments. In that spirit, students should argue for the explanations they construct, defend their interpretations of the associated data, and advocate for the designs they propose. (NRC Framework, 2012, p. 73)

Using Mathematics and Computational Thinking

Although there are differences in how mathematics and computational thinking are applied in science and in engineering, mathematics often brings these two fields together by enabling engineers to apply the mathematical form of scientific theories and by enabling scientists to use powerful information technologies designed by engineers. Both kinds of professionals can thereby accomplish investigations and analyses and build complex models, which might otherwise be out of the question. (NRC Framework, 2012, p. 65)


activity series - a list of metals or non-metals in order of decreased reactivity.

chemical change - any change that results in the formation of a new chemical substance.

coefficient - a number in front of a chemical substance that represents the quantity needed for a reaction.

combustion reaction - a type of chemical reaction that occurs when carbon and hydrogen compounds react with oxygen to produce carbon dioxide and water.

decomposition reaction - when one reactant breaks apart into two or more products.

double displacement reaction - a type of chemical reaction that occurs when the like ions of two ionic substances displace each other to form new substances; also known as a double replacement reaction.

law of conservation of matter - matter cannot be created or destroyed, it just changes from one form to another.

matter - anything that has mass and takes up space.

physical change - a change which alters a substance without altering its composition.

precipitate - a solid substance formed in a solution during a chemical reaction.

product - a substance formed as the result of a chemical reaction.

reactant - a substance that takes part in and undergoes change during a chemical reaction.

single displacement reaction - a type of chemical reaction that occurs by the transfer of electrons, so that a neutral substance displaces a like-charged ion in a compound so that it becomes neutral; also known as a single replacement reaction.

solubility table - a table which displays the ability of a substance to dissolve or dissociate in water or an acid.

synthesis reaction - a reaction that combines two or more reactants to form one product. 

Georgia Standards of Excellence

SC3Obtain, evaluate, and communicate information about how the Law of Conservation of Matter is used to determine chemical composition in compounds and chemical reactions.

SC3.aUse mathematics and computational thinking to balance chemical reactions (i.e. synthesis, decomposition, single replacement, double replacement, and combustion) and construct an explanation for the outcome of a simple chemical reaction based on the outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical properties.

SC3.bPlan and carry out investigations to determine that a new chemical has formed by identifying indicators of a chemical reaction (specifically precipitate formation, gas evolution, color change, water production, and changes in energy to the system should be investigated).

SPS3Obtain, evaluate, and communicate information to support the Law of Conservation of Matter.

SPS3.aPlan and carry out investigations to generate evidence supporting the claim that mass is conserved during a chemical reaction. (Clarification statement: Limited to synthesis, decomposition, simple replacement, and double replacement reactions.)

SPS3.bDevelop and use a model of a chemical equation to illustrate how the total number of atoms is conserved during a chemical reaction. (Clarification statement: Limited to chemical equations that include binary ionic and covalent compounds and will not include equations containing polyatomic ions.)

S8P1Obtain, evaluate, and communicate information about the structure and properties of matter.

S8P1.fConstruct an explanation based on evidence to describe conservation of matter and mass in a chemical reaction including the resulting differences between products and reactants. (Clarification statement: Evidence could include models with balanced chemical equations.)

Request Teacher Toolkit

The Chemistry Matters teacher toolkit provides instructions and answer keys for labs, experiments, and assignments for all 12 units of study. GPB offers the teacher toolkit at no cost to Georgia educators. Complete and submit this form to request the teacher toolkit. You only need to submit this form one time to get materials for all 12 units of study.