Chapter 8

Question 1

Periodic law

Answer 1

A law stating that when the elements are arranged by atomic number they exhibit a periodic recurrence of properties

Question 2

electron configuration

Answer 2

The distribution of electrons within the orbitals of the atoms of an element; also the notation for such a distribution

Question 3

spin quantum number(ms)

Answer 3

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

Question 4

exclusion principle

Answer 4

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 aha n orbital has a maximum occupancy of two electrons and their spins are paired

Question 5

shielding

Answer 5

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

Question 6

effective nuclear charge(Zeff)

Answer 6

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

Question 7

penetration

Answer 7

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

Question 8

orbital diagram

Answer 8

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

Question 9

Hund’s rule

Answer 9

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 10

transition elements

Answer 10

An element with atomic number higher that that of uranium

Question 11

inner(core) electrons

Answer 11

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 12

outer electrons

Answer 12

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

Question 13

valence electrons

Answer 13

The electrons involved in compound formation; in main-groups elements, the electrons in the valence level

Question 14

inner transition elements

Answer 14

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

Question 15

lanthanides

Answer 15

The period 6 series of inner transition elements, which includes cerium through lutetium

Question 16

actinides

Answer 16

The period 7 elements that constitute the second inner transition series, which includes thorium through lawrencium

Question 17

atomic size

Answer 17

One-half the distance between nuclei of two adjacent atoms in a sample of the element

Question 18

metallic radius

Answer 18

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

Question 19

covalent radius

Answer 19

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

Question 20

ionization energy

Answer 20

The energy required to remove completely one mole of electrons from one mole of gaseous atoms or ions

Question 21

electron affinity

Answer 21

The energy change accompanying the addition of one mole of electrons to one mole of gaseous atoms or ions

Question 22

amphoteric

Answer 22

Able to act as either an acid or a base

Question 23

isoelectronic

Answer 23

Having the same number and configuration of electrons as another species

Question 24

pseudo-noble gas configuration

Answer 24

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

Question 25

paramagnetism

Answer 25

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

Question 26

diamagnetism

Answer 26

The tendency of a species not to be attracted by a magnetic field as a result of its electrons being paired

Question 27

ionic radius

Answer 27

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