What is the trend in effective nuclear charge for elements on the periodic table?
It decreases across a period but is constant down a group.
It increases across a period but is constant down a group.
It is constant across a period but decreases down a group.
It is constant across a period but increases down a group.
Increase across a period (due to increasing nuclear charge with no accompanying increase in shielding effect).Decrease down a group (although nuclear charge increases down a group, shielding effect more than counters its effect).
