L.4 Periodic Table of Elements

Question 1

How is the periodic table arranged

1. How are the elements organized?
2. What are the rows?
3. What are columns?

Answer 1

1. Elements are organized according to their atomic number Z, this reveals a pattern of similar chemical and physical characteristics.
2. Rows = Periods; based on the same principal energy level, n.
3. Columns = Groups; have the same valence shell electron configuration.

Question 2

The elements on the periodic table belong to three types.

Answer 2

1. Metals are shiny, conduct electricity well, and are malleable and ductile.
2. Non Metals are dull, poor conductors of electricity, and are brittle.
3. Metalloids posses characteristics of both metals and non-metals.

Question 3

Effective Nuclear Charge

(Equation)

Answer 3

Nuclear charge (Z) is the total charge of all protons within the nucleus. It is therefore equal to the atomic number. Nuclear charge increases from left to right across the periodic table and from top to bottom down the periodic table. Effective nuclear charge (Zeff) is the net positive charge of an atom when electron shielding is considered. Electron shielding is the decrease in attraction from the nucleus experienced by valence electrons due to the presence of inner electrons between the nucleus and the valence electrons.

Effective nuclear charge is calculated by subtracting the number of non-valence electrons (S) from the nuclear charge (Z).

Zeff=Z−S

Effective Nuclear Charge Z_eff

is the net positive charge experienced by electrons in the valence shell and from the foundation for all periodic trends

Increases Rightward →

Little change in value from top to bottom in a group

Valence electrons become increasingly separated from the nucleus as the principal energy level increases, n, increases from top to bottom in a group.

Question 4

Atomic Radius

Answer 4

Atomic Radius

Increases Downward ↓

Increases Leftward ←

Question 5

Ionic Radius for

Cations

Anions

Metals

Non-metals

Metalloids

Answer 5

Ionic Radius is the size of a charged species.

Cations are generally smaller than their corresponding neutral atom

Anions are generally larger than their corresponding neutral atom

Metals lose elections and become +

Non-metals gain electrons and become -

Metalloids go in either direction, tend to follow the trend based on which side of the metalloid lone they fall on

Question 6

Ionization Energy

Answer 6

The amount of energy needed to remove an electron from the valence shell of a gaseous atom.

Increases from left to right across a period →

Increases from bottom to top ↑

Ionization energy is affected by

1. The distance of e from the nucleus
2. Z_eff
3. Nuclear chargre
4. Shielding

Question 7

Electron Affinity

Answer 7

Electron affinity is the amount of energy released when a gaseous species gain an election/change in energy that occurs when an atom of a neutral gas gains an electron.

Increases Rightward →

Increases Upward ↑

Question 8

Electronegativity

Answer 8

Electronegativity is a measure of the attractive force of the nucleus for electrons without a bond

Increases Rightward →

Increases Upwards ↑

Question 9

High reactivity to water

Answer 9

Alkali Metals & Alkaline Earth Metals

Question 10

Six Valence Electrons

Answer 10

Group 6 & Chalcogens/group 16

Question 11

Contain at least one metal

Answer 11

Groups 1 through 15

Question 12

Multiple oxidation states

Answer 12

All groups, but most noticeably transition metals ( groups 3-12)

Question 13

Negative Oxidation States

Answer 13

Almost all groups; mostly nonmetals (groups 14 -17)

Question 14

Poses full octet in neutral state

Answer 14

Group 18

Question 15

Paramagnetic

Answer 15

Electrons that are alone in an orbital are called paramagnetic electrons.

One or more unpaired electrons

Can be pulled into a magnetic field

Question 16

Diamagnetic

Answer 16

Any time two electrons share the same orbital, their spin quantum numbers have to be different.

All electrons are paired

Produces its own magnetic field

Question 17

What is a transition metal?

Answer 17

is an element whose atom has an incomplete D subshell or which can give rise to cations with incomplete subshells

Question 18

How do you know if an element is diamagnetic or paramagnetic?

Answer 18

Figuring out its electron configuration

Question 19

Pauline Scale

Answer 19

Electronegative difference scale