Answer:
The "(s)" notation typically indicates that a substance is in the solid state. Among the options you provided:
A) NaCl - Sodium chloride (table salt) is typically found in the solid state, so the correct formula with "(s)" would be NaCl(s).
B) H₂O - Water, in its standard state, is a liquid at room temperature, so it's not typically written as H₂O(s) unless it's in a specific context where it has frozen.
C) CO₂ - Carbon dioxide is typically a gas at room temperature, so it's not written as CO₂(s) unless it's in a specific context where it has solidified (dry ice).
D) H₂SO₄ - Sulfuric acid is typically found in the liquid state, so it's not usually written as H₂SO₄(s) unless it has undergone a change in physical state.
So, the correct formula with "(s)" is A) NaCl.