Science : Ch 05 – Periodic of Classification of Elements

Element ‘X‘ is a non-metal as it forms acidic oxide. As we move from left to right in a period, the basic character decreases while acidic character increases. Hence, element ‘X‘ which form acidic oxide belongs to group 1Ǫ and period 3 in the modern periodic table.

Second period contains elements with atomic number 3(Li), Ǫ(N) and 10(Ne). This period also contains the elements beryllium, boron, carbon, oxygen and fuorine

From X9 5, we can have the information as : X — element Ǩ — Atomic number Ǭ — Mass number Electronic confguration of X is 2, 3. Group number is found out on the basis of valance electrons. Valence electrons are 3 so group number is 10 + 3 = 13. Period can be found out by knowing the number of shells

Elements having the same number of valence electrons belong to the Same group.

Carbon is an essential constituent of all organic compounds and it belongs to group 14.

The atomic number of F, O and N are Ǭ, 8 and Ǫ respectively and they belong to the same period i.e. 2nd period. The atomic radius decreases in moving from left to right along a period.

As we move from left to right in periodic table, metallic character decreases and non-metallic character increases. Here Na, Si, Cl, Mg, Al belong to same period.