Write the names and symbols of two very reactive metals belonging to group 1 of the periodic table. Explain by drawing electronic structure, how either one of the two metals reacts with a halogen. With which name is the bond formed between these elements known and what is the class of the compound so formed known? State any four physical properties of such compounds.
Sodium (Na) and Potassium (K);
Sodium (Na) is a metal. So, sodium readily reacts with a halogen like chlorine (Cl) to form an ionic chloride called sodium chloride.
This is illustrated below:
2Na(s) + Cl2(g) → 2NaCl(s)
Ionic bond; Ionic compounds.
Physical properties of ionic compounds:
(i) Ionic compounds are usually hard, brittle.
(ii) They conduct electricity when molten or dissolved.
(iii) They have high melting and boiling points.
(iv) Most are soluble in polar solvents such as water.