Study the given table and answer the following questions. | Period | IA | IIA | IIIA | IVA | VA | VIA | VIIA | VIIIA (Zero Group) | |---|---|---|---|---|---|---|---|---| | 2nd | Li | Be | B | C | N | O | F | Ne | | 3rd | Na | Mg | Al | Si | P | S | Cl | Ar | i. Name any one metal with valency 3 and one non-metal with valency 2. ii. Which element is inert in the second period and why? iii. What change will occur in the atomic size of elements while moving from left to right in third period and why?
Answer (1)
i. Name any one metal with valency 3 and one non-metal with valency 2.
One metal with valency 3 is Aluminum (Al) from the 3rd period.
One non-metal with valency 2 is Oxygen (O) from the 2nd period.
ii. Which element is inert in the second period and why?
The inert element in the second period is Neon (Ne) . Neon is a noble gas, found in group VIII (Zero Group), and it is inert because it has a complete valence shell, with all eight electrons in its outermost energy level. This complete shell makes it very stable and unreactive under normal conditions.
iii. What change will occur in the atomic size of elements while moving from left to right in the third period and why?
As you move from left to right across the third period, the atomic size decreases . This decrease in size is due to the increasing positive charge of the nucleus as protons are added. The additional protons increase the nuclear charge, pulling the electrons closer to the nucleus and thus reducing the overall size of the atom, despite having the same energy level.
