Counting Atoms

Front

What is a balanced chemical equation?

Back

A balanced chemical equation has the same number of each type of atom on both sides of the equation, indicating that mass is conserved during the reaction.

Front

How do you determine if a chemical equation is balanced?

Back

Count the number of atoms of each element on both sides of the equation. If they are equal, the equation is balanced.

Front

What does the coefficient in a chemical equation represent?

Back

The coefficient indicates the number of molecules or moles of a substance involved in the reaction.

Front

How many hydrogen atoms are in H₂O?

Back

There are 2 hydrogen atoms in one molecule of water (H₂O).

Front

What is the formula for calculating the number of atoms in a compound?

Back

Multiply the subscript of each element by the coefficient in front of the compound.

Front

In the compound (NH₄)₂CrO₄, how many nitrogen atoms are present?

Back

There are 2 nitrogen atoms in (NH₄)₂CrO₄.

Front

What is the significance of subscripts in a chemical formula?

Back

Subscripts indicate the number of atoms of each element in a molecule.

Front

Is the equation 2Na + 2H₂O → 2NaOH + H₂ balanced?

Back

Yes, this equation is balanced because there are equal numbers of each type of atom on both sides.

Front

What does it mean if an equation is not balanced?

Back

It means that the law of conservation of mass is not being followed, as the number of atoms of each element is not the same on both sides.

Front

How many total atoms are in the compound Ca(NO₃)₂?

Back

There are 9 total atoms in Ca(NO₃)₂: 1 calcium, 2 nitrogen, and 6 oxygen.