Fill in the blanks from the choices given below:
(1) Across a period, the ionization potential ……. (increases/decreases/remains the same).
(2) Down the group, electron affinity……. (increase/decreases/remains the same).

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Solution

(1) Across a period, the ionization potential increases.
Concept:
Ionization energy or ionization potential is the minimum energy required to remove the most loosely bound electron of an isolated neutral gaseous atom or molecule.
On moving from left to right across a period, the ionization energy of elements increases.
This is due to the decrease in the size of atoms across a period. The valence electrons get closer to the nucleus of an atom as we move from left to right due to increased nuclear charge.
(2) Down the group, electron affinity decreases.
Concept:
Electron affinity is the amount of energy liberated when an electron is added to a neutral atom to form a negatively charged ion.
Electron affinity decreases down the groups because each atom is larger than the atom above it.
This means that an added electron is further away from the atom's nucleus compared with its position in the smaller atom.
It will be less attracted by the nucleus so less amount of energy will be released.

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Similar questions

Q. Fill in the blanks from the choices given below:
(i) Across a period, the ionisation potential __________ (increases, decreases, remains same).
(ii) Down the group, electron affinity _________ (increases, decreases, remains same).

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.

(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. 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. State whether the ionization potential increases or decreases on going down a group.

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) electro-negativity than sodium and the element above chlorine 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).

(d) Metals are good ............. (oxidising agent/ reducing agent) because they are electron.......... (acceptors/donors).

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Fill in the blanks from the choices given below:(1) Across a period, the ionization potential ……. (increases/decreases/remains the same).(2) Down the group, electron affinity……. (increase/decreases/remains the same).

Fill in the blanks from the choices given below:
(1) Across a period, the ionization potential ……. (increases/decreases/remains the same).
(2) Down the group, electron affinity……. (increase/decreases/remains the same).