The metal constituent of chlorophyll is

The reaction that takes place in soap making is called saponification. Basically soap is sodium or potassium salts of

When a copper rod is dipped in aqueous silver nitrate solution, the colour of the solution changes to blue. This is because

The image formed by a convex mirror of a real object is larger than the object

Match List 1 with List 2 and select the correct answer using the code given below the lists :

All the elements in a group (family) have a common valency. For example, all the elements of the carbon family (carbon, silicon, germanium, tin and lead ) have common valency four. However, some of these elements can also have valency two. Which of the following can have valency two?