Write the formulae of compounds that would be formed when the following pairs of elements combine.
(i) Mg and `N_(2)` (ii) Li and ` O_(2)` (iii) Ca and ` H_(2)`

Give the formulae of the stable binary compounds that would be formed by the combination of following pairs of elements. (a) Ca and N_(2) (b) Li and O_(2) (c ) Ca and Cl_(2) (d) K and O_(2)

Give the formulae of the stable binary compounds that wouid be formed by the combination of following pairs of elements. (a) Mg and N_(2)" " (b) Li and O_(2) (c) Al" and "Cl_(2)" (d) K and "O_(2)

Predict the formulae of the stable binary compounds that would be formed by the following pairs of compounds : (a) Al and Cl , (b) Mg and I (c ) Element 113 and F , (d) Si and S (e) Element 119 and oxygen.

Explain the following question (based on size of atoms or ions and other periodic properties): a. Arrange the following species in decreasing order of their sizes//ionic radii. i. Ar, K^(o+),Cl^(ɵ),S^(2-) and Ca^(2+) ii. Al^(3+), Mg^(2+),Na^(o+),Cl^(ɵ), N^(3-) and O^(2-) b. What are isoelectronic species? Name the species which are isoelectronic with each of the following atom or ions. i. Rb^(o+) ii. F^(ɵ) , iii. Mg^(2+) iv. Ar c. Arrange the following species // atoms in decreasing order of reducing character. i. Na, Mg and Al ii. Mg, Ca and Sr iii. Na, K and Rb iv. F^(ɵ), Cl^(ɵ),Br^(ɵ) and I^(ɵ) d. The decreasing order of reactivety of group 1 elements is Cs gt Rb gt K gt Na gt Li whereas that of group 17 elements is (Cl gt F gt Br gt I) . Explain. e. Predict the formula of the stable binary compounds that would be formed by the combination of the following pairs of elements: i. Mg and N ii. Si and O iii. Elements with Z=71 and F iv. P and F v. Al and I vi. Li and O f. Ansewer the following by the use of periodic table. i. Identify the element that would tend to gain two electrons. ii. Identify the group having metal, non-metal, liquid as well as gas at the room temperature, iii. Identify the element with five electrons in the outer shell. iv. Identify the element that would tend to lose two elctrons.

Classify the following into elements and compounds: (I) H_(2)O (ii) He (iii) Cl_(2) (iv) CO