WHAT is meant by the lanthanide contraction? Give two examples of its consequences?
The steady decrease in the size of the atoms and ions of the rare-earth elements with increasing atomic number from lanthanum (atomic number 57) through lutetium (atomic number 71) is known as the lanthanide contraction. The examples are: Hafnium is similar to zirconium in atomic radius and chemical behavior that it took more that 100 years after the discovery of zirconium for chemists to realize that hafnium was present as an impurity in every sample.
