To determine if the given equation representing the reaction of sodium with chlorine to produce sodium chloride is balanced, we need to follow these steps:
1. Write down the given equation:
[tex]\[ Na + Cl_2 \rightarrow 2 NaCl \][/tex]
2. Count the number of each type of atom on both sides of the equation.
- On the reactant side (left side of the arrow):
- Sodium (Na): 1 atom
- Chlorine (Cl): 2 atoms (since it is a diatomic molecule, [tex]\( Cl_2 \)[/tex])
- On the product side (right side of the arrow):
- Sodium (Na): 2 atoms (since there are 2 units of NaCl)
- Chlorine (Cl): 2 atoms (since each unit of NaCl contains 1 chlorine atom and there are 2 units of NaCl)
3. Compare the number of atoms for each element on both sides of the equation.
- Sodium (Na): There is 1 sodium atom on the reactant side and 2 sodium atoms on the product side.
- Chlorine (Cl): There are 2 chlorine atoms (represented by [tex]\( Cl_2 \)[/tex]) on the reactant side and 2 chlorine atoms on the product side.
4. Balance the equation if necessary. However, based on the count of atoms:
- Sodium is not balanced on both sides of the equation, and therefore the equation does not balance by itself.
Considering this, the correct choices for the given sentence are:
- The equation is balanced because the number of atoms is equal on both sides of the arrow.
Thus, we get:
"The equation is balanced because the number of atoms is equal on both sides of the arrow."