Ncert Exercises & Solutions

3.32 Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements.

(a) Lithium and oxygen

(b) Magnesium and nitrogen

(d) Silicon and oxygen

(e) Phosphorus and fluorine

(f) Element 71 and fluorine

$(a) L i O_{2} (b) M g_{3} N_{2} (c) A l I_{3} (d) S i O_{2} (e) P F_{3} o r P F_{5}$

(f) The element with the atomic number 71 is Lutetium (Lu). It has valency 3. Hence, the

formula of the compound is LuF $_{3}$ .