Page 20 - Science Course 3 (Book 2)

Mo8-L2b: Why is Mass Conserved in a Chemical Reaction?

Key Concept Mo8–L2b Why is Mass Conserved in a
How to Recognize Chemical Reactions? Chemical Reaction?
KEY CONCEPTS:
What happens to atoms during a chemical 1. What happens to the total mass in a chemical
reaction? reaction?

Vocabulary A-Z
Let us learn some vocabulary

chemical equation
a description of a reaction using element symbols
and chemical formulas.

reactant
the starting substances in a chemical reaction.

SUMMARY

How to Recognize Chemical Reactions?

A chemical reaction is a process in which
bonds break and atoms rearrange, forming
new bonds. product
the substances produced by the chemical reaction.

coef cient
a number placed in front of an element symbol or
chemical formula in an equation.

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