Question

what is the name of the compound na₂so₄?
sodium sulfide
sodium sulfur
sodium oxysulfide
sodium sulfate
question 4
which of the following is a polyatomic ion?
no₃⁻
o²⁻
na⁺
cl⁻

Explanation:

• For the first question:
• Sodium sulfide is \(Na_2S\).
• Sodium sulfur is not a correct compound name.
• Sodium oxysulfide is not a standard name for \(Na_2SO_4\).
• \(Na_2SO_4\) is composed of sodium (\(Na^+\)) and sulfate (\(SO_4^{2 -}\)) ions, so it is sodium sulfate.
• For the second question:
• A polyatomic ion is an ion composed of more than one atom.
• \(NO_3^-\) (nitrate ion) is composed of one nitrogen atom and three oxygen atoms.
• \(O^{2-}\), \(Na^+\), and \(Cl^-\) are monatomic ions (composed of a single atom).

Answer:

• First question: Sodium sulfate.
• Second question: \(NO_3^-\).