s-Block ElementsHard
Question
Which of the following statement is incorrect ?
Options
A.The atomic radius of Na is greater than that of Mg.
B.Metallic bond in Mg is stronger than the metallic bond in Na.
C.Melting and boiling points of Mg are greater than those of Ca.
D.Mg and Ca both impart characteristic colour to the flame.
Solution
(A) Along the period, the nuclear charge increases and, therefore, atomic size decreases. So Na has larger atomic radius than Mg.
(B) Mg is smaller than Na and Mg has two valence electrons per atom while Na has only one valence electron per atom. So Mg has stronger metallic bond than that of Na (Na is a soft metal).
(C) Because of stronger metallic bond in Mg than Ca, boiling and melting points of Mg are greater than Ca.
(D) Mg does not impart characteristic colour to the flame because the electrons in Mg are too strongly bound to get excited by flame. Ca imparts brick red colour to the flame because of its low ionisation enthalpy.
(B) Mg is smaller than Na and Mg has two valence electrons per atom while Na has only one valence electron per atom. So Mg has stronger metallic bond than that of Na (Na is a soft metal).
(C) Because of stronger metallic bond in Mg than Ca, boiling and melting points of Mg are greater than Ca.
(D) Mg does not impart characteristic colour to the flame because the electrons in Mg are too strongly bound to get excited by flame. Ca imparts brick red colour to the flame because of its low ionisation enthalpy.
Create a free account to view solution
View Solution FreeMore s-Block Elements Questions
White Mn(OH)2 becomes green coloured compound on reaction with sodium peroxide. It is :...What happens when sodium metal is heated to a temperature 350oC in excess of dry air containing carbon dioxide gas ?...Sodium metal can be stored under :...What are the products formed when an aqueous solution of magnesium bicarbonate is boiled ?...Flame test is not given by...