(a) Fluorine (F): Electronegativity increases across a period from left to right. Fluorine is the furthest to the right in Period 2 (excluding noble gases) and is the most electronegative element in the entire periodic table.
(b) Sodium (Na): Atomic size decreases across a period due to an increase in nuclear charge. Therefore, the element at the beginning of Period 3, Sodium, has the largest atomic radius in that period.
Which of the following element pairs will form an ionic bond? 
Rita added dilute hydrochloric acid to four metals. She recorded her observations in the table given below. While noting her observations she made some errors. 
Match Column A with Column B: 
नीचे दिए गए चित्र को ध्यान से देखिए और चित्र को आधार बनाकर कोई लेख, घटना अथवा कहानी लिखिए जिसका सीधा व स्पष्ट संबंध चित्र से होना चाहिए। 