Read the paragraph and answer the questions given below: In the modern periodic table, the elements are arranged in the increasing order of their atomic numbers. This arrangement is based on the modern periodic law, which states that the chemical and physical properties of elements are a periodic function of their atomic numbers. In the modern periodic table, each column is called a group and each row is called a period. Elements within the same group have similar chemical and physical properties. This is due to the same number of electrons in the outermost shell. For instance, alkali metals (Group 1 elements) have one electron in the outermost shell. They readily lose this electron to achieve stable electronic configuration and hence, alkali metals are very reactive. Similarly, all the noble gases (Group 18 elements) have completely filled outermost shell, which gives them extraordinary stability. i. State the law on which modern periodic table is based. ii. Why are alkali metals very reactive? iii. Which pair of elements do you think will have similar properties? a. Sodium and Argon b. Sodium and Potassium c. Potassium and Neon