Which of the following is the correct chemical formula for ammonium bromide?

• A. NH4B
• B. NH4Br
• C. NH4Br2
• D. NH3Br

Answer: (B)

Verified step by step guidance

1. Identify the ions involved in ammonium bromide: ammonium is a polyatomic cation with the formula \(\mathrm{NH_4^+}\), and bromide is a monatomic anion with the formula \(\mathrm{Br^-}\).
2. Recall that ionic compounds are electrically neutral, so the total positive charge must balance the total negative charge.
3. Since ammonium has a charge of +1 and bromide has a charge of -1, they combine in a 1:1 ratio to form a neutral compound.
4. Write the chemical formula by placing the cation first followed by the anion, resulting in \(\mathrm{NH_4Br}\).
5. Verify that the formula \(\mathrm{NH_4Br}\) correctly represents one ammonium ion combined with one bromide ion, making it the correct formula for ammonium bromide.