Chemical Bond
Knowledge-based Questions & Answers:
Ques-1. What is valency?
Ans: The capacity of bonding of an atom with another atom of an element while forming a molecule is called valency.
Ques-2. What is latent valency?
Ans: The difference between the highest valency and the active valency of an element is called its latent valency.
Ques-3. What is the structural formula?
Ans: The formula of expressing a molecule through the symbols and bonds of atoms, otherwise known as the organization of atoms, is called the structural formula.
Ques-4. What is the electronic configuration?
Ans: The electronic configuration is the distribution of electrons of an atom or molecule in atomic or molecular orbitals.
Ques-5. What are lone pair electrons?
Ans: The pair of electrons that do not remain bonded in the outermost shell of an atom is called the lone pair electrons.
Ques-6. What is bond energy?
Ans: The special bond with which the atoms in a molecule of elements remain bound to each other is called bond energy.
Ques-7. What is ionic bond energy?
Ans: The electrostatic force with which the cations and anions in an ionic compound remain bound is called ionic bond energy.
Ques-8. What type of bond is formed between metals and non-metals?
Ans: The ionic bond is formed between metals and non-metals.
Ques-9. What is the covalent bond?
Ans: The bond that is formed by sharing electrons between the atoms of non-metals in their outermost energy levels to obtain stable inert gas configurations is called a covalent bond.
Ques-10. What is a polar covalent compound?
Ans: The covalent compound in which polarity is created, is called a polar covalent compound.
Ques-11. What is a metallic bond?
Ans: The force of attraction that keeps the atoms in a piece of metal interconnected is called a metallic bond.
Comprehension-based Questions & Answers:
Ques-1. Why are inert gas elements chemically inert?
Ans: The group-18 elements of the periodic table are known as inert elements. The elements present in this group are – Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (X),and Radon (Rn). Since the required number of electrons in the outermost shells of these elements are fulfilled, they do not need to obtain stability by forming compounds through donating, accepting, or sharing of electrons. So, this element exhibits inert nature during bond formations or chemical reactions.
Ques-2. Why is NH+ a radical?
Ans: When a bundle of atoms from more than one element combine, receive positive or negative charges, and act as ion of an element, they are called radicals. NH+, is a radical since one N atom combines with four H atoms and forms a bundle of atoms that acts as a single atom and its charge is positive (+1). Therefore, NH+, is radical.
Ques-3. What do you understand by lone pair of electrons? Explain.
Ans: The pair of valence electrons that do not participate in chemical bond formation are called lone pair electrons. The unpaired electrons in the valence shells participate in chemical bond formation. For example, from the electronic configuration of oxygen
(O) atoms, it can be seen that. O(8)= 1s2 2s2 2p4
During chemical bond formation, the Py and Pz orbitals of valence energy level or second energy level participate in chemical bond formation whereas the electrons pairs in s and Px orbitals do not. The electrons in the latter orbitals are referred to as lone pair electrons.