chemistry : class12 Ionic Radii : Ionic solids : Solid State MCQ Questions and Answers
Practice important
Ionic Radii
MCQ questions and answers.
Page 1
of
1
|
10
MCQ Questions
1. Compared with its parent atom, the ionic radius of a cation is generally
A.
Smaller
B.
Larger
C.
Equal
D.
Always zero
Correct Answer:
Smaller
Explanation:
A cation forms by losing one or more electrons. The reduced electron cloud and often increased effective nuclear attraction make its ionic radius smaller than the atomic radius.
2. Compared with its parent atom, the ionic radius of an anion is generally
A.
Smaller
B.
Larger
C.
Equal
D.
Always zero
Correct Answer:
Larger
Explanation:
An anion forms by gaining electrons. Increased electron–electron repulsion expands the electron cloud, so its ionic radius is generally larger than the atomic radius.
3. Which particle has the smallest radius among Na, Na+, and Na−?
A.
Na
B.
Na+
C.
Na−
D.
All have the same radius
Correct Answer:
Na+
Explanation:
Na+ has lost an electron and has a smaller electron cloud than neutral Na, while Na− has gained an electron and is larger.
4. Which ion has the larger ionic radius: Na+ or K+?
A.
Na+
B.
K+
C.
Both have the same radius
D.
The neutral atoms have larger ionic radii
Correct Answer:
K+
Explanation:
Na+ and K+ are ions of the same group. K+ has an additional electron shell, so its ionic radius is larger than that of Na+.
5. Which ion has the larger ionic radius: F− or Cl−?
A.
F−
B.
Cl−
C.
Both have the same radius
D.
Neither ion has an ionic radius
Correct Answer:
Cl−
Explanation:
Cl− lies below F− in the halogen group and has one more occupied electron shell. Therefore, Cl− has the larger ionic radius.
6. Which order correctly represents the ionic radii of Li+, Na+, and K+?
A.
Li+ < Na+ < K+
B.
K+ < Na+ < Li+
C.
Na+ < Li+ < K+
D.
Li+ = Na+ = K+
Correct Answer:
Li+ < Na+ < K+
Explanation:
For ions of the same charge in a group, ionic radius increases down the group because additional electron shells are added.
7. Which of the following is larger in size?
A.
Mg2+
B.
O2−
C.
Both have the same ionic radius
D.
Neither has a measurable radius
Correct Answer:
O2−
Explanation:
Mg2+ and O2− are isoelectronic, but Mg2+ has more protons and attracts the same number of electrons more strongly. Thus, O2− has the larger ionic radius.
8. Among the isoelectronic ions Na+, Mg2+, and Al3+, which has the smallest ionic radius?
A.
Na+
B.
Mg2+
C.
Al3+
D.
All have equal ionic radii
Correct Answer:
Al3+
Explanation:
These ions have the same number of electrons. Al3+ has the greatest nuclear charge, so it attracts the electron cloud most strongly and has the smallest ionic radius.
9. Which statement about the ionic radius of a cation is correct?
A.
It is generally smaller than the radius of its atom
B.
It is always larger than the radius of its atom
C.
It is always equal to the radius of its atom
D.
It does not depend on electron loss
Correct Answer:
It is generally smaller than the radius of its atom
Explanation:
Loss of electrons reduces electron–electron repulsion and may remove an outer shell, causing the cation to have a smaller radius than its parent atom.
10. Which sequence shows increasing ionic radius correctly?
A.
Al3+ < Mg2+ < Na+
B.
Na+ < Mg2+ < Al3+
C.
Mg2+ < Na+ < Al3+
D.
Al3+ < Na+ < Mg2+
Correct Answer:
Al3+ < Mg2+ < Na+
Explanation:
Na+, Mg2+, and Al3+ are isoelectronic. As nuclear charge increases from Na+ to Al3+, ionic radius decreases, giving Al3+ < Mg2+ < Na+.
Short Questions and Answers
Practice short questions and answers related to
Ionic Radii
.
Short questions are currently unavailable for this page.