To determine the correct formula for the ionic compound formed by sodium (Na) and sulfur (S), we need to consider the charges of the ions each element forms when they interact.
1. Determine the charges of the ions:
- Sodium (Na): Sodium, which is in Group 1 of the periodic table, loses one electron to form a cation with a charge of +1. The ionic form of sodium is [tex]\( Na^+ \)[/tex].
- Sulfur (S): Sulfur, which is in Group 16 of the periodic table, gains two electrons to form an anion with a charge of -2. The ionic form of sulfur is [tex]\( S^{2-} \)[/tex].
2. Balance the charges:
- For the compound to be electrically neutral, the total positive charge must equal the total negative charge.
- Since each sodium ion has a charge of +1, and each sulfur ion has a charge of -2, we need two sodium ions to balance the charge of one sulfur ion.
- [tex]\( 2 \times Na^+ = 2 \times (+1) = +2 \)[/tex]
- [tex]\( 1 \times S^{2-} = 1 \times (-2) = -2 \)[/tex]
3. Write the formula:
- Combining two [tex]\( Na^+ \)[/tex] ions and one [tex]\( S^{2-} \)[/tex] ion, we get the neutral formula [tex]\( Na_2S \)[/tex].
Therefore, the correct formula for the ionic compound formed from sodium and sulfur is [tex]\( Na_2S \)[/tex].
Given the options:
1. [tex]\( Na_2S \)[/tex]
2. [tex]\( NaS_2 \)[/tex]
3. [tex]\( Na_2S_2 \)[/tex]
4. [tex]\( NaS \)[/tex]
The correct answer is:
[tex]\( Na_2S \)[/tex], which corresponds to the first option.
