Select the one lettered choice that best fits each statement. A choice may be used once, more than once, or not at all in each set. The following questions refer to the below molecules: (A) CO2 (B) H2O (C) CH4 (D) C2H4 (E) PH3 The molecule with the largest dipole moment

b. first ionization energy

Explanation:

Therefore, moving left to right across a period the nucleus has a greater pull on the outer electrons and the atomic radii decreases. Moving down a group in the periodic table, the number of filled electron shells increases. ... Therefore, the positive nucleus pulls the electrons tighter and the radius is smaller.