Write the names and symbols of two most reactive metals belongiong to group I of the periodic table. Explain by drawing electronic structure how either one of the two metals reacts with halogen. With which name is the bond formed between these elements known and what is the class of the compuond so formed known? state any four physical properties of such compounds.

Two elements X and Y have atomic numbers 12 and 16 respectively. Write the electronic configuration for these elements. To which period of the modern perioidic table to these two elements belong? What type of bond will be formed between them and why?

A colloidal solution is a type of mixture which consists of particles whose size varies between 1 and 1000 nanometres. In colloidal solution the particles are distributed evenly. During this process the particles do not settle down. This is one of the best know thing about colloidal solutions. Properties of colloids and their variation are a well-known area ever since the primitive age. The best example to prove their familiarity with us is that we know from very early times that coagulation of milk results in the formation of curd. Physical properties of colloids 1. The nature of the colloidal solution is heterogeneous i.e. unlike. These solutions dwell with two different phases : • Dispersed medium Dispersed phase. 2. Despite the fact that colloidal dispersions are unlike in description (nature), yet the dispersed fragments are not detectabJe by the human eye. This is due to the microscopic size of the particles in the solution. 3. The colour of the colloidal dispersion is determined by particles in the solution based on their size. The wavelengths of light that is absorbed will be longer ifthe size of the particle is large. 4. As a result of its size, the colloidal fragments can easily be passed through a traditional filter paper. However, these particles can be filtered by using membranes such as animal, cellophane, and ultrafilters. Give the name of membrane used for filteration ?