Which symbols are used to indicate the physical state of substances in a chemical reaction equation?

• A. , , ,
• B. {s}, {l}, {g}, {aq}
• C. [s], [l], [g], [aq]
• D. (s), (l), (g), (aq)

Answer: (D)

Verified step by step guidance

1. Understand that in chemical reaction equations, the physical state of each substance is indicated by specific symbols placed in parentheses immediately after the chemical formula.
2. Recognize the common physical state symbols: (s) for solid, (l) for liquid, (g) for gas, and (aq) for aqueous solution (a substance dissolved in water).
3. Note that these symbols are always enclosed in parentheses, not brackets or angle brackets, to clearly denote the state without confusion.
4. For example, water as a liquid is written as H\_2O(l), and sodium chloride dissolved in water is NaCl(aq).
5. Therefore, the correct notation for physical states in chemical equations uses the symbols (s), (l), (g), and (aq).