Chapter 8 Definitions

Question 1

Different periodic properties of elements?

Answer 1

Atomic Radius, Ionization Energy, Electron Affinity

Question 2

Elements in a column have the same number of valence electrons and chemical properties. True/False

Answer 2

True

Question 3

Core Electrons

Answer 3

Those in complete principal energy levels and those in complete d and f sublevels

Question 4

The row number in the periodic table is equal yo the number n (highest principal level). True/False

Answer 4

True

Question 5

Alkali Metals

Answer 5

Tend to lose one electron. Have one valence electron. Most reactive metals

Question 6

Alkaline Earth Metals

Answer 6

Have two valence electrons. Tend to lose two electrons

Question 7

Halogens

Answer 7

Have seven valence electron. Tend to gain one electron. Most reactive nonmetals

Question 8

Noble Gases

Answer 8

Have eight valence electrons except from helium (2 valence electrons). They are stable and unreactive.

Question 9

Van der Waals Radius

Answer 9

Represents the radius of an atom when it is not bonded to another atom. Radius of an atom is one half the distance between adjacent nuclei

Question 10

Atomic Radii Trend

Answer 10

As we move down a column (family), atomic radii increases.(n, principal quantum number increases)
As we move to the right across a period (row), atomic radii decreases.( greater effective nuclear charge)

Question 11

Fact on Effective Nuclear Charge

Answer 11

Cations with more charge have lower potential energy. So, they have a smaller ion.

Question 12

Effective Nuclear Charge

Answer 12

The average or net charge experienced by an electron. Nucleus charge - # of core electrons. The greater the effective nuclear charge the smaller the radius

Question 13

Slater Rules

Answer 13

To calculate the shielding constant for a given electron

Question 14

Lanthanide Contraction

Answer 14

The size of Lanthanide ions and atoms decrease moving left to right across the periodic table. Result of poor shielding effect of the 4f electrons.

Question 15

Ionic Radii Trend

Answer 15

An increase in cation means a decrease in size. Cations are smaller than their corresponding atoms.
An increase in anion means an increase in size. Anions are larger than their corresponding atoms.
The greater the protons means a smaller radius even if they have the same electrons. The less protons means a larger radius even if they have the same electrons

Question 16

Ionization Energy

Answer 16

Energy required to remove an electron from the atom or ion in the gaseous state. Electrons easier to remove means lower ionization energy

Question 17

First Ionization Energy

Answer 17

Energy required to remove the first electron

Question 18

Second Ionization Energy

Answer 18

Energy required to remove the second electron

Question 19

Third Ionization Energy

Answer 19

Energy required to remove the third electron

Question 20

Ionization Energy Trend

Answer 20

It decreases as we move down a column.
It increases as we move right across a period. Electrons in the outermost principal energy experience a greater effective nuclear charge

Question 21

Exceptions to the Ionization Energy Trend

Answer 21

Boron has a smaller Ionization energy than Beryllium
Aluminum has a smaller ionization energy than Gallium
Oxygen has a lower ionization energy than nitrogen
s and se.
Ionization energies in transition metals increases as we move down a group

Question 22

Electron Affinity

Answer 22

A measure of how easily an atom will accept an additional electron. This is important in chemical bonding. Energy released when an electron is added to a neutral atom in the gas phase(positive quantity)

Question 23

Electron Affinity trend

Answer 23

Generally have no group trends
Electron Affinities become lower as me move down a column (group 1)
Electron Affinities becomes more positive as we move right across a row.

Question 24

Metallic Trends

Answer 24

Metallic Character decreases as we move to the right across a period