Chapter 8 Vocab

Question 1

Spin quantum numbe (ms)

Answer 1

A number, either +1/2 or -1/2, that indicates the direction of electron spin.

Question 2

Pauli exclusion principle

Answer 2

A principle developed by Wolfgang Pauli stating that no two electrons in an atom can have the same set of four quantum numbers. The principle arises from the fact that an orbital has a maximum occupancy of two electrons and their spins are paired.

Question 3

Shielding

Answer 3

(Also screening) The ability of other electrons, especially those occupying inner orbitals, to lessen the nuclear attraction for an outer electron.

Question 4

Effective nuclear charge (Zeff)

Answer 4

The nuclear charge an electron actually experiences as a result of shielding effects due to the presence of other electrons.

Question 5

Penetration

Answer 5

The phenomenon in which an outer electron moves through the region occupied by the core electrons to spend part of its time closer to the nucleus; penetration increases the average effective nuclear charge for that electron.

Question 6

Aufbau principle

Answer 6

The conceptual approach for building up atoms by adding one proton at a time to the nucleus and one electron to the lowest energy sublevel that is available, to obtain the ground-state electron configurations of the elements.

Question 7

Orbital diagram

Answer 7

A depiction of orbital occupancy in terms of electron number and spin shown by means of arrows in a series of small boxes or on a series of short lines.

Question 8

Hund’s rule

Answer 8

A principle stating that, when orbitals of equal energy are available, the electron configuration of lowest energy has the maximum number of unpaired electrons with parallel spins.

Question 9

Transition element

Answer 9

An element that occupies the d block or the f block (inner transition element) of the periodic table.

Question 10

Inner electrons

Answer 10

(Also core electrons) electrons that fill all the energy levels of an atom except the valence level; electrons also present in atoms of the previous noble gas and any completed transition series.

Question 11

Outer electrons

Answer 11

Electrons that occupy the highest energy level (highest n value) and are, on average, farthest from the nucleus.

Question 12

Valence electrons

Answer 12

The electrons involved in compound formation; in main-group elements, the electrons in the valence (outer) level.

Question 13

Inner transition elements

Answer 13

The elements of the periodic table in which the seven inner f orbitals are being filled; the lanthanides and the actinides.

Question 14

Lanthanides

Answer 14

(Also rare earths) The Period 6 (4f) series of inner transition elements, which includes cerium (Ce; Z=58) through lutetium (Lu; Z=71).

Question 15

Actinides

Answer 15

The Period 7 events that constitute the second inner transition series (5f block), which includes thorium (Th; Z=90) through lawrencium (Lr; Z=103).

Question 16

Atomic size

Answer 16

A measure of how closely one atom lies next to another, determined from the distances between nuclei of adjacent atoms (see also metallic radius and covalent radius).

Question 17

Metallic radius

Answer 17

One-half the shortest distance between the nuclei of adjacent individual atoms in a crystal of an element.

Question 18

Covalent radius

Answer 18

One-half the shortest distance between nuclei of identical covalently bonded atoms.

Question 19

Ionization energy (IE)

Answer 19

The energy (in kJ) required for complete removal of 1 mol of electrons from 1 mol of gaseous atoms or ions.

Question 20

Electron affinity (EA)

Answer 20

The energy change (in kJ) accompanying the addition of 1 mol of electrons to 1 mol of gaseous atoms or ions.

Question 21

Amphoteric

Answer 21

Able to act as either an acid or a base.

Question 22

Isoelectronic

Answer 22

Having the same number and configuration of electrons as another species.

Question 23

Pseudo-noble gas configuration

Answer 23

The (n-1)d^10 configuration of a p-block metal ion that has an empty outer energy level.

Question 24

Paramegnetism

Answer 24

The tendency of a species with unpaired electrons to be attracted by an external magnetic field.

Question 25

Diamagnetism

Answer 25

The tendency of a species not to be attracted (or to be slightly repelled) by a magnetic field as a result of its electrons being paired.

Question 26

Ionic radius

Answer 26

The size of an ion as measured by the distance between the nuclei of adjacent ions in a crystalline ionic compound.