## Classification of Elements and Periodicity in Properties Questions and Answers Part-6

1. The second ionization potential of an element M is the energy required to
a) remove one mole of electrons from one mole of gaseous cations of the element
b) remove one mole of electrons from one mole of gaseous anions
c) remove one mole of electrons from one mole of monovalent gaseous cations of the element
d) remove 2 moles of electrons from one mole of gaseous atoms

Explanation: remove one mole of electrons from one mole of monovalent gaseous cations of the element

2. Highest ionization potential is shown by
a) Alkali metals
b) Transition elements
c) Halogens
d) Inert gases

Explanation: Inert gases due to completely filled and stable. s2p6 configuration show highest I.E.

3. With reference to ionization potential which one of the following sets is correct?
a) Li > K < Cs
b) B > Li > K
c) Cs > Li > B
d) Cs < Li < K

Explanation: B > Li > K

4. Which of the following species has lowest ionization potential?
a) O
b) $O_{2}$
c) $O_2^+$
d) $O_2^-$

Explanation: The additional p -molecular electron in $O_2^-$ is added to the less stable antibonding orbital. Hence, it is easy to remove that electron from $O_2^-$ ion. Thus I.E. (I.P.) of $O_2^-$ is lowest.

5. The factor not affecting the ionization energy is
a) size of atom
b) charge in the nucleus
c) type of bonding in the crystalline lattice
d) type of electron involved

Explanation: type of bonding in the crystalline lattice

6.The screening effect of inner electrons of the nucleus causes
a) decrease in the ionization energy
b) increase in the ionization energy
c) no effect on the ionization energy
d) increases the attraction of the nucleus for the electrons

Explanation: Higher the screening effect, lower is the I.E

7. Consider the following statements
I. The radius of an anion is larger than that of the parent atom.
II. The ionization energy generally increases with increasing atomic number in a period.
III. The electronegativity of an element is the tendency of an isolated atom to attract an electron.
Which of the above statements is/are correct?
a) I alone
b) II alone
c) I and II
d) II and III

Explanation: I and II

8. Which of the following order is wrong
a) $NH_{3}<PH_{3}<AsH_{3}$     —Acidic
b) Li < Be < B < C    —$IE_{1}$
c) $AI_{2}O_{3}<MgO<Na_{2}O<K_{2}O$        —Basic
d) $Li^{+}<Na^{+}<Ki^{+}<Cs^{+}$     —Ionic radius

Explanation: The right sequence of I.E1 of Li < B < Be < C.

9. Gradual addition of electronic shells in the noble gases causes a decrease in their
a) ionization energy
c) boiling point
d) density