Which of the following fourth-period elements has the smallest atomic radius?
A)K
B)Ti
C)Cu
D)Ge
E)Kr

Question

Quizplus · Accepted Answer

As we move from left to right across a period, the number of protons in the nucleus increases, increasing the effective nuclear charge and attracting the electrons towards the center. This reduces the size of the atom. Among the given elements, Kr is on the right side of the period and has the highest effective nuclear charge, making it the smallest in size. Therefore, choice E (Kr) has the smallest atomic radius.

Which of the Following Fourth-Period Elements Has the Smallest Atomic