Which of the following is a $1:2$ type compound?

Which of the following metals has a $ccp$ crystal structure?

In a cubic structure of a compound made from $X$ and $Y$,where $X$ atoms are at the corners of the cube and $Y$ atoms are at the face centers of the cube,the molecular formula of the compound is:

What is the value of the radius ratio for an ionic crystal having a coordination number of $6$?

In $FCC$ lattice,alternate tetrahedral voids are occupied in which of the following?

In the fluorite structure,the coordination number of $Ca^{2+}$ ion is