Chemistry Midterm 2: Chapter 8

Front 1

Penetration

Back 1

The closer the smaller maxima lies to the nucleus, the greater the attractive force is

Front 2

Different sub shells, and general trend

Back 2

s>p>d>f. Because of penetration though, the 3d orbital has a higher energy than the 4s orbital.

Front 3

Spin quantum number

Back 3

The fourth quantum number (Ms). Only has two values: +/- 1/2.

They describe the magnetic fields which electrons generate according to the direction of their spin.

two electrons can exist in the same atomic orbital as long as they have opposite spins

Front 4

Pauli exclusion principle

Back 4

No two electrons can have the same four quantum numbers

Front 5

Aufbau Principles

Back 5

Electrons generally will occupy the most stable atomic orbitals (lowest energy)

Front 6

Hund's Rule

Back 6

In the case of degenerate orbitals, electrons will prefer to occupy different degenerate atomic orbitals rather than be paired up in the same atomic orbital.

Front 7

Energy differences of the d and f orbitals

Back 7

In non filled electron energy diagrams, the ns orbital is lower in energy than the (n-1)d orbital and (n-2)f orbitals.

Front 8

Valence shell

Back 8

The sub shells in the highest energy levels of an atom

Front 9

Valence electrons

Back 9

The electrons that fill the orbitals (s-f) in the valence shell

Front 10

Core electrons

Back 10

Electrons not in the valence shell (inner shell). They do not readily interact with other electrons

Front 11

Favourable electron configuration

Back 11

Half filled sub shell. Filled sub shell. Noble gas configuration.

Front 12

Half filled sub shell

Back 12

Where all orbitals within a given sub shell are half filled

Front 13

Filled sub shells

Back 13

Where all orbitals within a given sub shell are filled. When two electrons occupy the s sub shell in heavier elements, they are much less reactive, and is referred to as an inert pair effect. When electrons fully occupy the s sub shell and combination of f and d sub shells, the f and d shells drop in energy below the energy of the valence shell. These elections are now non reactive and are considered pseudo core electrons

Front 14

Noble Gas Configuration

Back 14

Where all orbitals in the valence shell are filled. Highly favourable.

Front 15

Valence shell electron configuration and short hand notations

Back 15

Essentially you take the noble gas with the closest configuration and edit its valence shell

eg. Cs -> [Xe]....

Front 16

Notable exceptions in electron configurations (Cu)

Back 16

One is copper the d sub shell will be filled at the expense of un-pairing the electrons in the s sub shell.

Front 17

Notable exceptions in electron configurations (Cr)

Back 17

In the electron configuration of chromium the d sub shell will be half-filled at the expense of un-pairing the electrons in the s sub shell

Front 18

Common oxidation states for atoms: group 1

Back 18

elements in this group will form +1 cations to attain a noble gas configuration or form a -1 anion (filled s sub shell, called an inert pair)

Front 19

Common oxidation states for atoms: group 2

Back 19

Elements in this group will a +2 cation in order to attain a noble gas configuration

Front 20

Common oxidation states for atoms: main group elements

Back 20

Can have many oxidation states, but will gain or lose electrons in order to reach a noble gas configuration

Front 21

Common oxidation states for atoms: Most transition metals

Back 21

Will form a +2 cation from the loss of the ns sub shell

Front 22

Idea of Triads

Back 22

Johann Wolfgang Dobereiner. Elements with similar properties

Front 23

Law of octaves

Back 23

John Newlands - similar properties which appear every 8 elements

Front 24

Periodic Law

Back 24

Mandeleev - ranked the known elements by atomic mass and grouped according to similar properties

Front 25

Henry Mosely

Back 25

Ranked elements in terms of atomic number from x-ray studies (instead of atomic mass)

Front 26

Important aspects of the periodic table: groups

Back 26

Groups are elements that occur in the same vertical column. Groups 1 and 2 are called s block. Groups 3-12 are called the d block. Groups 13-18 are called the p block.

Front 27

Important aspects of the periodic table: periods

Back 27

Periods are elements occurring in the same horizontal row. Period number is related to a particular valence shell.

Front 28

Periodic Trends: Atomic Radii

Back 28

2 different ways to define the general size of an atom. i) non-bonding atomic radius, describes half the distance between two atoms in a solid state lattice. ii) Bonding atomic radius describes half the distance between two atoms that are connected through a chemical bond. As you move down a group, the radii increases. As you move left to right the radii decreases, from an increased Zeff.

Front 29

Periodic Trends: Ionic Radii (cations)

Back 29

Cations: upon losing electrons and forming a cation, the remaining electrons are much more attractive to the nucleus, and are thus pulled closer to the nucleus. Cations are generally smaller than their initial atoms. Increased positive charge = smaller ionic radius. As you move left to right across a period, ionic radius of isoelectronic ions decreases.

Front 30

Periodic Trends: Ionic radii (anions)

Back 30

Upon gaining an electron, an atombecomes negatively charged and the electrons are more repulsive to one another, therefore: generally anions are larger. Increased negative charge = larger anion.

Front 31

Periodic Trends: Ionization energy

Back 31

The ionization energy is defined as the energy required to remove an electron from an atomin the gaseous state. Always refers to highest energy electron present (high profile). Ionization energy is always positive.

Front 32

Periodic Trends: Electron Affinity

Back 32

The electron affinity (EA) is defined as the energy that is released when a gaseous atomgains an electron. In most cases the EA is positive.

Front 33

Periodic Trends: Electronegativity

Back 33

Electronegativity is similar to electron affinity, except that electronegativity is defined asthe capability of an atom to attract electrons in a covalent bond towards itself. Atoms that have a large first ionization energy, as well large positive electron affinity willhave a high electronegativity value.

Front 34

Periodic Trends: Metallic Character (metals)

Back 34

There is a division amongst groups in the periodic table. metals, non-metals, and metalloids. Conductors of electricity and heat. Metals are also ductile. Metals also shiny and readily loseelectrons during chemical reactions.

Front 35

Periodic Trends: Metallic Character (Non-metals)

Back 35

Poor Conductors of electricity of heat. Non-Metals can exist as a solid, aliquid or a gas. Non-Metals also gain electrons in chemical reactions

Front 36

Periodic Trends: Metallic Character (Metalloids)

Back 36

Elements which exhibit mixed characteristics between metals and non-metals. Metalloids are often good semiconductors.

Front 37

Periodic Trends: Metallic properties

Back 37

Paramagnetic elements: defined as an element whose atoms or ions contain unpairedelectrons. Diamagnetic elements: defined as an element whose atoms or ions contain only pairedelectrons.

Front 38

Periodic Trends: Reactivity patterns

Back 38

In general, the element which is more electronegative will accept electrons from theelement that is less electronegative.