Periodic Trend: Effective Nuclear Charge

Choose the statement that is TRUE.   a) Outer electrons efficiently shield one another from nuclear charge. b) Core electrons effectively shield outer electrons from nuclear charge. c) Valence electrons are most difficult of all electrons to remove. d) Core electrons are the easiest of all electrons to remove. e) All of the above are true

Which of the following statements is TRUE?   A. An orbital that penetrates into the region occupied by core electrons is less shielded from nuclear charge than an orbital that does not penetrate and therefore has a lower energy.  B. An orbital that penetrates into the region occupied by core electrons is more shielded from nuclear charge than an orbital that does not penetrate and therefore has a lower energy. C. It is possible for two electrons in the same atom to have identical values for all four quantum numbers. D. Two electrons in the same orbital can have the same spin. E. None of the above are true.

In which orbital below would an electron (on average) be closest to the nucleus? a. 2p b. 4s c. 2s d. 5d e. 3p

What factor best explains the reduction in the effective nuclear charge (Z eff) experienced by the outermost electrons of a multi-electron atom?   (a) Orbital splitting by the increased nuclear charge. (b) The outermost electrons are moving too quickly to feel the full pull of the nucleus. (c) Hund’s rule. (d) The inner electrons shield the outer electrons from the nuclear charge. (e) Pauli’s exclusion principle.

Electrons in the 1s subshell are much closer to the molecules in Ar than in He due to the larger ______ in Ar. a) azimuthal quantum number b) paramagnetism c) magnetic quantum numbers d) Hund's rule  e) nuclear charge

Screening by the valence electrons in atom is ______. a) responsible for a general increase in atomic radius going across a period. b) less efficient than that by core electrons c) essentially identical to that by core electrons d) more efficient than that by core electrons  e) both more efficient than that by core electrons  and responsible for a general increase in atomic radius going across a period

In which orbital does an electron in a phosphorus atom experience the greatest shielding _____? a) 3p b) 3s c) 2p d) 2s e) 1s

Arrange the following atoms according to decreasing effective nuclear charge experienced by their valence electrons S, Al, Si, Mg a. S > Al > Si > Mg  b. Mg > Al > Si > S c. Al > S > Si> Mg  d. S > Si > Al > Mg e. Si > Al > Mg > S

The radii of the ions in this series decrease because a) the elements are in the same period. b) the effective nuclear charge is increasing. c) the atomic radius of Na decreases  from Na to Al. d) the first ionization energies increase from Na to Al.

In which orbital below would an electron (on average) be closest to the nucleus?A) 2pB) 2sC) 3pD) 4sE) 5d 

In which orbital below would an electron (on average) be farthest from the nucleus? A) 4f B) 2p C) 3d D) 3s E) 1s  

The effective nuclear charge for an atom is less than the actual nuclear charge due to ________.a. shieldingb. paramagnetismc. electron-pair repulsiond. penetratione. relativity

Which would you expect to experience a greater effective nuclear charge, a 2p electron or a 2s of an atom? a. 2s electron of an atomb. 2p electron of an atomc. Both experience the same effective nuclear charged. Requires a table of shielding constants to make an estimation

Calculate Zeff for the 4s electron in a copper atom, Cu. Express your answer numerically.

Rank the following elements by effective nuclear charge, Z eff, for a valence electron from highest to lowest Zeff:Po, Rn, Ba, Bi, Pb (same as ionization energy)

In which orbital does an electron in a phosphorus atom experience the greatest effective nuclear charge?a) 1sb) 2sc) 2pd) 3se) 3p

In which orbital does an electron in a lithium atom experience the greatest shielding?

Rank the following elements by effective nuclear charge, Z eff, for a valence electron.Kr, Se, Ca, K, Ge