Question

Statement I: Calcium oxide is a covalent substance.
Statement II: When a metal reacts with a non-metal, a covalent bond is formed.
A.Statement 1 and Statement 2 are correct and statement 2 is the correct explanation of Statement 1.

B.Both Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation of Statement 1.

C.Statement 1 is correct but statement 2 is not correct.

D.Statement 1 is not correct but Statement 2 is correct.

E.Both Statement 1 and Statement 2 are not correct.

Answer 1

Hint: Covalent bond is formed by the sharing of electrons between the participating atoms. The pair of electrons participating in this type of bonding is called a shared pair or bonding pair. Bonding of sharing atoms must have a similar outer shell electronic configuration. With this we can determine the above statement.

Complete step by step answer:
Calcium oxide is ionic because it is formed between a metal and non-metal and bonds formed between a metal and non-metal atoms are ionic.
Determination of bonding in compounds:
A bond formed between a metal and nonmetal atom is ionic.
A bond formed between nonmetal atoms is covalent.
The bonding formed between the same non-metal atoms is a nonpolar covalent bond.
Covalent bonds are formed between the different atoms.
Bonds formed between the atoms of metals are metallic bonds.
Bonds formed between two molecules that are coordinate covalent bonds.
In calcium oxide, the electronic configuration of the calcium atom is :
Atomic number of $Ca=20$
$Ca=1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^2$
Calcium has two valence electrons in its outermost shell and loses two electrons to attain the nearest noble gas configuration.
The electronic configuration of $C{a}^{2+}$ ion:
Atomic number of $C{a}^{2+}=18$
$C{a}^{2+}=1s^{2}2s^{2}2p^{6}3s^{2}3p^6$
In the case of oxygen, the atomic number is 8 and the electronic configuration of the oxygen atom in its ground state is:
  $O=1s^{2}2s^{2}2p^4$
The oxygen atom requires two more electrons to attain the nearest noble gas configuration.
$O^{2-}=1s^{2}2s^{2}2p^6$
In this, the calcium can lose two electrons and oxygen accept two electrons. Thus calcium gives its two valence electrons to oxygen and forms an ionic bond with oxygen.
An ionic bond formed when one atom transfers one or more electrons from itself to its neighboring atom, and an ionic bond formed between the two atoms of the compound.
The calcium oxide forms ionic bonds due to the valence electrons.
Thus Statement 1 is incorrect.
When a metal reacts with non-metal it forms an ionic bond.
Thus Statement 2 is incorrect.
Thus the correct answer is (E).

Note:
The strength of the covalent bond is greater than the ionic bond because in a covalent bond there is a mutual sharing of valence electrons and in an ionic bond there is a transfer of valence electrons in the outer shell. The order of the bond strength from weakest to strongest: Van der Waals, Hydrogen, Ionic, Covalent.