Let's analyze the given question to understand the significance of the number '4' in the formula [tex]\(4 \mathrm{Na}_2\mathrm{SO}_3\)[/tex], which represents sodium sulfite.
We begin by breaking down the given options one by one.
1. There are four atoms of sodium.
- In the formula [tex]\( \mathrm{Na}_2\mathrm{SO}_3 \)[/tex], each molecule contains 2 sodium atoms. If there are 4 units of [tex]\( \mathrm{Na}_2\mathrm{SO}_3 \)[/tex], it would mean [tex]\( 4 \times 2 = 8 \)[/tex] sodium atoms. Therefore, this option is incorrect.
2. There are four atoms of sodium sulfite.
- Sodium sulfite ([tex]\( \mathrm{Na}_2\mathrm{SO}_3 \)[/tex]) is a compound, not an individual atom. Therefore, this option is also incorrect because you can't have 4 atoms of a compound.
3. There are four molecules of sodium sulfite.
- In the chemical notation, the number in front of a formula represents the number of molecules. Hence, [tex]\(4 \mathrm{Na}_2\mathrm{SO}_3\)[/tex] means there are 4 molecules of sodium sulfite. This option correctly represents the significance.
4. There are four elements in sodium sulfite.
- Sodium sulfite ([tex]\( \mathrm{Na}_2\mathrm{SO}_3 \)[/tex]) consists of 3 different elements: sodium ([tex]\( \mathrm{Na} \)[/tex]), sulfur ([tex]\( \mathrm{S} \)[/tex]), and oxygen ([tex]\( \mathrm{O} \)[/tex]). So, this statement is also incorrect.
From the above analysis, the correct interpretation of the '4' in the formula [tex]\(4 \mathrm{Na}_2\mathrm{SO}_3\)[/tex] is:
There are four molecules of sodium sulfite.
Thus, the correct option is:
Option 3: There are four molecules of sodium sulfite.
