Chapter 4:

Which of the following options correctly describes the shielding effects in a many-electron systems? a.) Shielding reduces the magnitude of the nuclear charge a given electron experiences. b.) Inner electrons are more effective at shielding outer electrons than electrons in the same level. c.) The shielding effect increases with an increasing number of electrons in a given sublevel. d.) Electrons in the same sublevel do not shield each other from the nucleus. e.) Shielding protects an electron so that it is harder to remove from the atom.

Answer explanation

a, b, c

Which of the following statements correctly describes the changes that occur as we move from left to right across the periodic table? a.) Nuclear charge increases b.) The number of core electrons increases. c.) The nuclear charge felt by the outermost electrons decreases d.) The number of valence electrons increases for representative elements.

Answer explanation

a, d

Order the following elements in terms of increasing effective nuclear charge (Zeff) Br Cs K As

Answer explanation

K Ca As Br

Repulsions between electrons in a many-electron atom results in a phenomenon known as ______________, which leads to the electrons "experiencing" a lower____________ nuclear charge.

Which type of electrons are best at shielding a 3p electron? 3d 3p 3s 2p 4p

Answer explanation

2p bc Electrons in inner energy levels are best at shielding other electrons

As we move from left to right in the periodic table the effective nuclear charge (Zeff) __________ because the number of ___________ electrons remains the same while the actual nuclear charge increases.

Based on their positions in the periodic table, match the elements that are most chemically similar. K Cs Mg Cl F Sr Ne Ar

Answer explanation

K Cs Mg Sr F Cl Ne . Ar

Arrange the following elements in order of increasing atomic size, starting with the smallest atom at the top of the list. I Se S Br

Answer explanation

S Br Se I

Elements such as Na and K are in the same ________________ of the periodic table. These elements have similar chemical properties because they have the same number of __________ electrons.

Match the group number from the periodic table with the correct name. Elements in Groups 1A - 7A Group 8A Elements in Groups 18 and 3B f- block transition elements ____________________________________________ transition metals noble gases lanthanides and actinides main group elements