Question

An element X forms a divalent cation. Write the chemical formula of its oxide and chloride.​

Answer 1

Answer:

(a) The electronic configuration of element 'X' with atomic number 17 is 2,8,7. Since, it has 7 valence electrons. Therefore, it lies in group 17 (10 + 7). Further, since in element X, third shell is being filled, it lies in third period. In other wordds, X is chlorine

The electronic configuration of element 'Y' with atomic number 20 is 2,8,8,2. Since, it has 2 valence electrons, it lies in group 2. Further, since in element Y, fourth shell is being filled, it lies in `4^(th)` period. In other words, Y is calcium.

(b) Since, element X (i.e., Cl) has seven electrons in the valence shell and needs one more electron complete its octet. Therefore it is non-metal. Further , since element Y ionic compounds, therefore, the nature of n = 7]. The electron dot structure of divalent metal halide, i.e., `CaCl_(2)` is