Introductory Chemistry III Course Materials & Test Answers | vle.mona.uwi.edu

Fill in the blanks

Lanthanide Contraction: The electron configuration of every third-row d-block metal, there are 4f electrons. These extra electrons along with the extra protons cause

third-row

second-row

first-row

d-block metals to be more similar in size to the second-row d-block metals. The expected large increase in size in going from the

third

second

first

to

third

second

first

row is not observed due to the

increase

decrease

in the effective nuclear charge experienced by the valence electrons, brought about because of

efficent

inefficient

shielding by

s

f

d

p

electrons.

E.g. Given the atomic radii of the copper and silver to be 157 pm and 175 pm respectively, the atomic radius of gold can be estimated to be pm which is

smaller

bigger

than expected.

Electron configurations: Cu - [Ar] 3d¹⁰ 4s¹ ; Ag - [Kr]4d¹⁰5s¹ ; Au - [Xe]4f¹⁴5d¹⁰6s¹