(a) What is the electronic configuration of (i) a sodium atom, and (ii) an oxygen atom?
(b) What is the number of outermost electrons in (i) a sodium atom, and (ii) an oxygen atom?
(c) show the formation of Na_2O by the transfer of electrons between the combining atoms.
(d) Why are ionic compounds usually hard?
(e) How is it that ionic compounds in the solid state do not conduct electricity but they do so when in molten state?
(a) What is the electronic configuration of (i) a sodium atom, and (ii) an oxygen atom?
(b) What is the number of outermost electrons in (i) a sodium atom, and (ii) an oxygen atom?
(c) show the formation of Na_2O by the transfer of electrons between the combining atoms.
(d) Why are ionic compounds usually hard?
(e) How is it that ionic compounds in the solid state do not conduct electricity but they do so when in molten state?
Answer :
(a) (i) Atomic number of Sodium is 11.
Its electric configuration is 
K L M - 2 8 1.
(ii) Atomic number of oxygen is 8.
Its electronic configuration is K L - 2, 6.
(b) (i) In a sodium atom, the number of electrons present in its outermost shell (M shell) is one.
(ii) In a oxygen atom, the number of electrons present in its outermost shell (M shell) is Six.
(c)
(d) Ionic compounds are usually hard because they are held together by strong electrostatic forces of attraction. Therefore the oppositely charged ions pack tightly with each other and form a crystalline structure which is very hard to break down
(e) When ionic compounds are in a molten state or dissolved in water, forming an aqueous solution, the ions that formed the ionic compounds are able to move around freely, thus able to conduct electricity.
Answer :
(a) (i) Atomic number of Sodium is 11.
Its electric configuration is K L M - 2 8 1.
(ii) Atomic number of oxygen is 8.
Its electronic configuration is K L - 2, 6.
(b) (i) In a sodium atom, the number of electrons present in its outermost shell (M shell) is one.
(ii) In a oxygen atom, the number of electrons present in its outermost shell (M shell) is Six.
(c)
(d) Ionic compounds are usually hard because they are held together by strong electrostatic forces of attraction. Therefore the oppositely charged ions pack tightly with each other and form a crystalline structure which is very hard to break down
(e) When ionic compounds are in a molten state or dissolved in water, forming an aqueous solution, the ions that formed the ionic compounds are able to move around freely, thus able to conduct electricity.
