Trends in Ionization Energy

Q.

Which element from the following has the highest ionisation energy ?

(a) P, Na, Cl (b) F, O, Ne (c) Ne, He, Ar

Explain your choice.

Q.

Parts (a) to (e) refer to changes in the properties of elements on moving from left to right across a period of Periodic Table. For each property, choose the correct answer.

(a) The non-metallic character of the elements :

(i) decreases, (ii) increases,

(iii) remains the same, (iv) depends on the period

(b) The electronegativity :

(i) depends on the number of valence electrons,

(ii) remains the same,

(iii) decreases,

(iv) increases.

(c) The ionization potential :

(i) goes up and down (ii) decreases

(iii) increases (iv) remains the same

(d) The atomic size :

(i) decreases,

(ii) increases,

(iii) remains the same ,

(iv) sometimes increases and sometimes decreases.

(e) The electron affinity of the elements in groups 1 to 7 :

(i) goes up and then down.

(ii) decreases and then increases,

(iii) increases,

(iv) decreases.

Q.

Which of the following has the lowest ionization energy?

1. Nitrogen

2. Fluorine

3. Sulfur

4. Oxygen

Q. Within a group, where would you expect to find the element with:
(i) the greatest metallic character?
(ii) the largest atomic size?

Q.

Which of the following does not form ${\mathrm{M}}^{3+}$ more easily among group 13 elements?

1. $\mathrm{B}$

2. $\mathrm{Al}$

3. $\mathrm{Ga}$

4. $\mathrm{In}$

Q.

Name the element with maximum electron affinity.

Q. Part (i) to (v) refer to changes in the properties of elements on moving from left to right across a period of the periodic table. For each property, choose the letter corresponding to the correct answer from the choices (a), (b), (c) and (d).
(i) The non-metallic character of the elements:
(a) decreases
(b) increases
(c) remains the same
(d) depends on the period

(ii) The electronegativity:
(a) depends on the number of valence electrons
(b) remains the same
(c) decreases
(d) increases

(iii) The ionisation potential:
(a) goes up and down
(b) decreases
(c) increases
(d) remains the same

(iv) The atomic size:
(a) decreases
(b) increases
(c) remains the same
(d) sometimes increases and sometimes decreases

(v) The electron affinity of the elements in groups 1 to 7:
(a) goes up and then down
(b) decreases and then increases
(c) increases
(d) decreases

Q.

The metal of group 2 from top to bottom are Be, Mg, Ca, Sr and Ba. Which of these elements will form ions most readily and why?

Q. Choose the correct answer from the alternative given.
Match the column I with column II and mark the appropriate choice.

	Column I		Column II
(A)	Element with highest second ionisation enthalpy	(i)	Cr
(B)	Element with highest third ionisation enthalpy	(ii)	Cu
(C)	M in $M(CO{)}_6$ is	(iii)	Zn
(D)	Element with the highest heat of atomisation	(iv)	Ni

1. (A) - (ii), (B) - (iii), (C) - (i), (D) - (iv)
2. (A) - (iv), (B) - (iii), (C) - (i), (D) - (ii)
3. (A) - (iii), (B) - (i), (C) - (ii), (D) - (iv)
4. (A) - (i), (B) - (ii), (C) - (iii), (D) - (iv)

Q. The electronegativities (according to Pauling) of the elements in period 3 of the periodic table are as follows. The elements are arranged in alphabetical order:

Al	Cl	Mg	Na	P	S	Si
1.5	3.0	1.2	0.9	2.1	2.5	1.8

(i) Arrange the elements in the order in which they occur in the periodic table from left to right. (The group 1 elements first, followed by the group 2 element and so on, up to group 7.)
(ii) Choose the word or phrase from the brackets which correctly completes each of the following statements:
(a) The element below sodium in the same group would be expected to have a _________ (lower/higher) electronegativity than sodium and the element above chlorine which would be expected to have a ________ (lower/higher) ionization potential than chlorine.
(b) On moving from left to right in a given period, the number of shells _________ (remains the same/increases/decreases).
(c) On moving down a group, the number of valence electrons __________ (remains the same/increases/decreases).

Q.

The $I{P}_1,I{P}_2,I{P}_3,I{P}_4,I{P}_5$ of an element are 7.1, 14.3, 34.5, 46.8, 162.2 eV respectively. Which element among the following would that be?

1. Na

2. Ca

3. Si

4. F

Q. Arrange the following elements in the increasing order of first ionisation enthalpies.

1. Lithium (Li)
2. Potassium (K)
3. Caesium (Cs)
4. Sodium (Na)

Q. Which of the following sequence of explanation is appropriate for explaining the reason for the periodicity of reducing property in a period or group?
(a) Tendency to undergo oxidation decreases in a period and increases in a group.
(b) In a period ionization energy increases and in a group it decreases.
(c) In a period the atomic size decreases and in a group it increases.
(d) The elements present in the left side of the periodic table have strong reducing property.

1. c b a d
2. d c a b
3. c d b a
4. d b a c

Q.

What are trands ?

Q. Among the given option, enthalpy of atomisation is maximum for ? -----a) Ti , b) V , c) Cr , d) Fe

Q.

The $I{P}_1,I{P}_2,I{P}_3,I{P}_4,I{P}_5$ of an element are 7.1, 14.3, 34.5, 46.8, 162.2 eV respectively. Which element among the following would that be?

1. F

2. Si

3. Ca

4. Na

Q. Which of the following reasons correctly justifies that fluorine has higher ionisation energy than lithium?​

Q. Which of the following pair is expected to exhibit same colour in solution?

1. $CuC{l}_2$; $VOC{l}_2$
2. $VOC{l}_2$; $FeC{l}_2$
3. $MnC{l}_2;FeC{l}_2$
4. $FeC{l}_2;CuC{l}_2$

Q. Choose the correct statements.

i. Ionisation energy of sodium is less than that of magnesium.

ii. Atomic size of sodium is less than that of magnesium.

iii. Metallic character of sodium is greater than that of magnesium.

iv. Reactivity of sodium is less than the reactivity of magnesium.

[1 mark]

1. (i) and (ii)
2. (i) and (iii)
3. (ii) and (iv)
4. (ii) and (iii)

Q.

The metals of group two from top to bottom are : Be, Mg, Ca, Sr, Ba.

Which of these metals will form ions most readily and why?

Q. Z effective decreases down a group. Then why would first group elements like Na, K and Rb have same Zeffective(2.2) except Lithium?