Counting Atoms & Balancing Equations

Front

What is a chemical equation?

Back

A chemical equation is a symbolic representation of a chemical reaction, showing the reactants and products along with their quantities.

Tags

NGSS.MS-PS1-5

Front

What does it mean to balance a chemical equation?

Back

Balancing a chemical equation means ensuring that the number of atoms for each element is the same on both sides of the equation.

Tags

NGSS.MS-PS1-5

Front

What are coefficients in a chemical equation?

Back

Coefficients are numbers placed in front of the chemical formulas to indicate how many molecules or moles of a substance are involved in the reaction.

Front

How do you determine the number of atoms in a compound?

Back

To determine the number of atoms in a compound, look at the subscripts in the chemical formula. If there is no subscript, it means there is one atom of that element.

Tags

NGSS.MS-PS1-1

Front

What is the subscript in a chemical formula?

Back

A subscript is a small number written to the right of an element symbol in a chemical formula, indicating the number of atoms of that element in a molecule.

Front

How many oxygen atoms are in Al(OH)3?

Back

There are 3 oxygen atoms in Al(OH)3.

Tags

NGSS.MS-PS1-1

Front

What is the balanced equation for the reaction of carbon monoxide and iron(III) oxide?

Back

The balanced equation is 3CO + Fe2O3 --> 2Fe + 3CO2.

Tags

NGSS.MS-PS1-5

Front

Why is the equation H2 + O2 --> H2O not balanced?

Back

It is not balanced because there are 2 oxygen atoms on the left side and only 1 on the right side.

Tags

NGSS.MS-PS1-5

Front

What is the balanced equation for the reaction of sodium and water?

Back

The balanced equation is 2Na + 2H2O --> 2NaOH + H2.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Front

What happens if a chemical equation is not balanced?

Back

If a chemical equation is not balanced, it does not accurately represent the conservation of mass, meaning the number of atoms is not the same on both sides.

Tags

NGSS.MS-PS1-5