An alloy of Cu, Ag, and Au is found to have Cu constituting the CCP lattice. If Ag atoms occupy edge centers, and Au is present at the body centre, then the alloy has a formula

\(Cu_4Ag_3Au\)

The correct answer is 3. \(Cu_4Ag_3Au\).

Cu forming CCP, so the number of Cu (ions)= 4

Ag occupies the edge centre, so the number of Ag \( = 12 × \frac{1}{4} = 3\)

Au present at body centre, so number of Au = 1

Thus, the formula of the compound = \(Cu_4Ag_3Au\)