Answer
Please see the work below.
Work Step by Step
The group 1B elements are Cu, Ag, and Au, and the group 1A elements (alkali metals) are Li, Na, K, Rb, Cs, and Fr.
The group 1B elements are characterized by the poor shielding effect of inner core electrons, and hence valence shell electrons are effectively attracted by the nucleus. They also possess higher ionization enthalpy than alkali metals due to the poor shielding effect. Hence the group 1B elements are more stable than alkali metals.
