Question

1. the correct chemical formula for copper (ii) chlorite is

cu(clo₂)₂
cu(clo₂)₄

1. the correct chemical formula for astatine tribromide is

atbr₃
at₃br₃

1. the correct chemical formula for sodium hydroxide is

naoh
naoh₂

1. the correct chemical formula for chromium (iii) chloride is

crcl₃
cr₃cl₃

Explanation:

Question 2

Step1: Determine ion charges

Copper (II) has a charge of \(+2\) (\(Cu^{2+}\)), chlorite ion is \(ClO_2^-\).

Step2: Balance charges

To balance \(+2\) and \(-1\), we need 2 chlorite ions. So formula is \(Cu(ClO_2)_2\).

Step1: Analyze prefixes

"Astatine tribromide" – astatine (At) has no prefix (1 atom), tribromide means 3 bromine (Br) atoms.

Step2: Form formula

Combine 1 At and 3 Br: \(AtBr_3\).

Step1: Identify ions

Sodium ion is \(Na^+\), hydroxide ion is \(OH^-\).

Step2: Balance charges

\(+1\) and \(-1\) balance in a 1:1 ratio, so formula is \(NaOH\).

Answer:

\(Cu(ClO_2)_2\) (the first option)

Question 3