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Flashcards in Chapter 8 Deck (27):
1

Periodic law

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

2

electron configuration

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

3

spin quantum number(ms)

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

4

exclusion principle

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

5

shielding

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

6

effective nuclear charge(Zeff)

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

7

penetration

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

8

orbital diagram

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

9

Hund's rule

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

10

transition elements

An element with atomic number higher that that of uranium

11

inner(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

12

outer electrons

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

13

valence electrons

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

14

inner transition elements

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

15

lanthanides

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

16

actinides

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

17

atomic size

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

18

metallic radius

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

19

covalent radius

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

20

ionization energy

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

21

electron affinity

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

22

amphoteric

Able to act as either an acid or a base

23

isoelectronic

Having the same number and configuration of electrons as another species

24

pseudo-noble gas configuration

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

25

paramagnetism

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

26

diamagnetism

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

27

ionic radius

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