Question

15. The elements of one short period of the Periodic Table are given below in order from left to right. Li Be B C O F Ne
(i) To which period do these elements belong?
(ii) One element of this period is missing. Which is the missing element and where should it be placed?
(iii) Which one of the elements in this period shows the property of catenation?
(iv) Place the three elements fluorine, beryllium and nitrogen in the order of increasing electro-negativity.
(v) Which one of the above elements belongs to the halogen series?

Answer 1

Ans : - (i) second period 
(ii) nitrogen (N) is missing. This element should be placed between carbon and oxygen 
(iii) carbon (C) shows the property of catenation 
(iv) beryllium, nitrogen and fluorine 
(v) fluorine (F).

Answer 2

Answer:

Periodic table is a tabular array of chemical elements arranged in the order of their atomic number in rows and columns

Explanation:

(i)These element belongs to the second period in periodic table.

(ii)Nitrogen is missing and its place is-

Li Be B C N O F Ne

(iii)Carbon shows the property of Catenation

(iv)F>N>Be in the order of increasing electronegativity.

(v)Fluorine is belong to the halogen series.

• Catenation is the property of an element to bind itself through covalent bond and give rise to a single large structure or chain.
• Electronegativity is a tendency of an element to attract the atom for bonding electrons in molecules compared to that of other atoms.
• On moving left to right electronegativity increases across the periodic table.