2. The Periodic Table

Question 1

In the periodic table, what are are periods?

Answer 1

rows, based on the energy level n

Question 2

In the periodic table, what are are groups?

Answer 2

based on the columns.

Elements in the same group have the same valence shell electron configuration.

Question 3

What’s the difference between representative elements and non-representative elements?

Answer 3

Representative (A): Groups IA through VIIIA, they have electrons in the orbitals of either s or p shells

Non-Representative Elements (B): Include transition elements which has valence electrons in the s and d subshells;
Lanthanide and Actinide Series: has valence electrons in the s and f subshells

Question 4

In what three groups can elements loosely be grouped into?

Answer 4

Metals, non-metals, metalloids (semiconductors, semimetals)

Question 5

What are the three types of metals that metals can be classified into?

Answer 5

Active metals (valence in s or p subshell)
Transition metals (valence in s or d subshell)
Lanthanide Series/Actinide Series (valence in s or f subshell)

Question 6

What are some characteristics of metals?

Answer 6

1. Shiny
2. conduct energy well
3. Malleable
4. Ductile
5. Generally solid (except mercury)

Trends: low effective nuclear charge, low ionizing energy, low electron affinity, large atomic radius, small ionic radius, high electropositivity/low electronegativity

Question 7

What are some characteristics of non-metals? (x3)

Answer 7

1. dull
2. poor conductors of electricity and heat
3. Brittle

Question 8

What are some characteristics of metalloids?

Answer 8

1. Electronegativities and ionizing energies lie between those of metals and non-metals
2. Physical properties vary widely
3. Reactivities depend on the element with which they are reacting.

Question 9

What is the effective nuclear charge? How is it defined?

What is the Z_{eff of Oxygen, fluourine, and sodium?}

Answer 9

Definition: Zeff= net positive charge experienced by electrons in the valence shell
Definition: The electrostatic attraction between the valence shell electrons and the nucleus.

Note, its calculated with the electrons NOT in the outer shell.

Zeff of Oxygen= 8-2= +6
Zeff of Fluorine=9-2= +7
Zeff of sodium=11-10= +1

Question 10

What is the trend for the effective nuclear charge?

Answer 10

1. Increases from left to right (because there are more protons)
2. No change going from top to bottom.

Question 11

How do you define the atomic radius?

Answer 11

Definition: 1/2 the distance between the centers of two atoms of an element that are briefly in contact with each other

Atomic Radius the the size of a neutral element, DIFFERENT FROM ionic radius which is dependent on how the element ionizes

Question 12

What is the trend of the atomic radius?

Answer 12

1. Decreases left to right
2. Increases top to bottom

The bottom left hand corner has the biggest radius, the left hand upper corner has the largest radius.

This makes sense. The more protons you have, the more the pull on the outer electron group. So those in group 1 have fewer protons than group 8, so less pull of the electrons inward, and larger atomic radius.

Question 13

What is the definition of the ionic radius?

Answer 13

The size of the radius of a charged element (or ion).

This is opposed to atomic radius, which is the size of the radius of normal element (non-charged.

Question 14

What are the trends of the ionic radius?

Answer 14

Not too specific.

The more electrons you have, the bigger the radius.
The less electrons you have, the smaller the radius.

Cations: Smaller than their corresponding neutral atom (lose electron)
Anions: larger than corresponding neutral atom (gain electron)

Question 15

How do you define the ionization energy?

Answer 15

Definition: the amount of energy necessary to remove an electron from the valence shell of a gaseous species.

Definition 2: (google): ionization energy, also called ionization potential, in chemistry and physics, the amount of energy required to remove an electron from an isolated atom or molecule.

They are related to electronegativity: the lower the ionization energy, the lower the electronegativity; the higher the ionization energy, the higher the electronegativity.

Question 16

What’s the trend of ionization energy?

Answer 16

1. Increases from left to right
2. Decreases from top to bottom

Remember: the greater the Zeff, the greater ionization energy required.
Remember: second ionization energy will always be greater than the first ionization energy.

Question 17

What is the definition of electron affinity?

Answer 17

Definition 1: The amount of energy released when a gaseous species gains an electron in its valence shell

Definition 2: electron affinity, in chemistry, the amount of energy liberated when an electron is added to a neutral atom to form a negatively charged ion. The electron affinities of atoms are difficult to measure, hence values are available for only a few chemical elements, chiefly the halogens.

This is opposite of ionization energy (Ion= amount of energy to lose an electron, electron affinity= energy released when you gain an electron)

Think of this energy in relation to how bad they want the electron. Group 1 and two don’t really want the electron, so they have low affinity and lower amount of energy released. Group 7 wants them, so have high electron affinity.

Question 18

What are the trends of electron affinity?

Answer 18

Increases from left to right (they really want that electron as you go to the right to fill up the outer shell)

Those in group 8 have low to no electron affinity, because their outer shell is full

Question 19

What is the definition of electronegativity?

Answer 19

It’s the measure of the attractive force between the nucleus from electrons within a bond

They are related to ionization energies: the lower the ionization energy, the lower the electronegativity; the higher the ionization energy, the higher the electronegativity.

Question 20

What is the trend of electronegativity?

Answer 20

it increases from left to right across a period and decreases from top to bottom in a group.

Question 21

What are the trends in:
1. Electronegativity
2. Ionization energy
3. electron affinity
4. Atomic radius

Answer 21

All the same except atomic radius, which is opposite.

Question 22

What group is A1 called?

Answer 22

Alkali metals

Question 23

What group is IIA called?

Answer 23

Alkaline earth metals

Question 24

What group is VIA called?

Answer 24

The chalcogens

Question 25

What group is VIIA called?

Answer 25

The halogens

Question 26

What group is VIIIA called?

Answer 26

Nobel gases

Question 27

What group are IB-VIIIB called?

Answer 27

Transition metals.

Question 28

What’s the oxidation state of Alkali metals?

Answer 28

Group 1A
Typically +1

Question 29

What are the most reactive metals?

Answer 29

Group 1A, they want to lose that electron the most!

Alkali Earth Metals

Question 30

What is the oxidation state of alkaline earth metals?

Answer 30

Group IIA
oxidation State of +2 (typical)

Question 31

What are the oxidation states of the chalcogens?

Answer 31

These really vary.
Oxidation states from -2 to +6

Question 32

What are the oxidation states of halogens?

Answer 32

Group VIIA.
Highly reactive, oxidation state of -1
They have the highest electronegativities.

Question 33

What group has the highest electronegativity and electron affinity?

Answer 33

The halogens, group VIIA