Question

#2

a)

In the Si4 + cation, what is the effective charge seen by a valence electron?

b)

In the Si4- anion, what is the effective charge seen by a valence electron?

c)

Among S2-, Cl-, Ar, K +, Ca2 +, Se2-, Br-, Kr, Rb +, and Sr2 +, which has the smallest radius?

d)

Which of S2-, Cl-, Ar, K +, Ca2 +, Se2-, Br-, Kr, Rb +, and Sr2 + has the greatest ionization energy?

Answer 1

a. Effective Charge:- The actual charge or reduced Nuclear charge experienced by a valence electron after the screening, is called Effective charge.

It is represented by "Zeff

And it is calculated by formula :-

Zeff = Z - Screening constant

Where Z is the atomic number and Screening constant is the shielding effect of inner lying electrons.

c. Atomic radius decreases if we move left to right in a period due to increase in effective nuclear charge while atomic radius increases as we move down the group due to addition of new shell. Atomic radius decreases if the ion ( cation ) carry more and more positive charge on it.

d. ionisation energy is defined as "The amount of energy required to remove valence electron from an isolated gaseous atom or ion. Ionisation energy is maximum or greater when size of atom/Ion is small , Ion carry more and more positive charge on it and it has noble gas or noble gas like electronic configuration.

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