Some data on the properties of Group I elements are given below. Lithium has a melting point of $181\,^{\circ}\text{C}$ and a density of $0.53\,\text{g cm}^{-3}$. Sodium has a melting point of $98\,^{\circ}\text{C}$ and a density of $0.97\,\text{g cm}^{-3}$. Potassium has a melting point of $X$. Rubidium has a melting point of $Y$ and a density of $Z$. What are the values of $X$, $Y$ and $Z$?
- A$X=63$, $Y=252$, $Z=0.26$
- B$X=63$, $Y=39$, $Z=0.26$
- C$X=39$, $Y=63$, $Z=1.53$
- D$X=63$, $Y=39$, $Z=1.53$