Periodicity

Question 1

Atomic Radius

Answer 1

Decreases left to right across a period 
-increasing core charge 
-stronger attraction between nucleus and valence electrons
-decreases in size (becomes smaller)
Increases down a group
-increasing filled energy levels

Question 2

Ionic Radius

Answer 2

For metals: decreases left to right across a period
-metals lose an electron to become more stable
For non-metals: increases left to right across a period
-non-metals gain an electron to become more stable
-more repulsion between the electrons making it gain in size

Question 3

First Ionization Energy

Answer 3

Increases left to right across a period
-higher core charge
-stronger attraction between nucleus and valence electrons
Decreases down a group
-increasing atomic radius
-weaker attraction between nucleus and valence electrons

Question 4

Electronegativity

Answer 4

Increases across a period left to right
-core charge increases which attracts electrons
Decreases down a group
-increase in atomic radius
-valence shell is further away from nucleus
-more difficult to attract electrons

Question 5

Electron Affinity

Answer 5

Increases across a period left to right

Decreases down a group

Question 6

Metallic Character

Answer 6

Decreases across a period left to right
-increasing electronegativity
-increasing number of protons
-increasing core charge 
Increases down a group 
-reactivity decreases 
-ionization decreases

Question 7

Melting Point (Alkali Metals)

Answer 7

Increases across a period left to right
-higher core charge
-stronger attraction between electrons and nucleus
Decrease down a group
-increase in atomic radius
-weaker attraction between electrons and the positive nucleus

Question 8

Equation for Electron Affinity

Answer 8

F(g) + e- –> F-(g)

Question 9

Definition of First Electron Affinity

Answer 9

Energy released when one mole of electrons are added to one mole of gaseous atoms to form one mole of gaseous 1- ions.

Question 10

First Ionization Energy Definition

Answer 10

Energy required to remove one mole of electrons from one mole of gaseous atoms to form one mole of gaseous 1+ ion.

Question 11

First Ionization Energy Equation

Answer 11

X(g) –> X+ (g) + e-

Question 12

Second Ionization Energy Equation

Answer 12

X+ (g) –> X+2 (g) + e-

Question 13

Second (or higher) Ionization Energy Definition

Answer 13

Energy required to remove one mole of electrons from one mole of gaseous ions

Question 14

Definition of Electronegativity

Answer 14

The attraction between the atoms and the electrons to form a covalent bond.