1.7-1.8

Question 1

Effective Nuclear Charge

Answer 1

Zeff = Z - (alpha)
Zeff = the charge experienced by an electron
Z = actual nuclear charge (atomic #)
alpha = shielding constant (0<) (<Z)

Question 2

Periodicity

Answer 2

Predictable physical and chemical trends that occur moving across a period or down a group

Question 3

When does atomic radius increase?

Answer 3

Down a group, left on a row

Question 4

Five characteristics of valence electrons moving down a group:
- Energy, stability, distance, shielding, effective nuclear charge

Answer 4

-More energy
-Less stable
-Greater distance from nucleus
-Greater shielding effect
-Decreased effective nuclear charge

Question 5

Metals ____ electrons to form cations

Answer 5

lose

Question 6

Nonmetals ____ electrons to form anions

Answer 6

gain

Question 7

Cations are ____ than neutral atoms

Answer 7

smaller

Question 8

Anions are ____ than neutral atoms

Answer 8

larger

Question 9

Three characteristics of atomic radius moving across a group:
-Valence electrons
-Shielding
-Coulomb’s law

Answer 9

-Valence electrons are in the same shell
-Shielding effect experienced by outer electrons is similar so the addition of protons increases Zeff
-More protons are added, force of attraction experienced by each electron increases

Question 10

First ionization energy

Answer 10

Minimum amount of energy required to remove the least tightly held electron from an atom or ion in the gas phase.

Question 11

Energy must be ____ to remove an electron

Answer 11

added

Question 12

When does first ionization energy increase?

Answer 12

Moving up a column, and generally moving across a row.
*Generally increases as atomic radii decrease

Question 13

Two exceptions to the generality that first ionization energy increases as atomic radii decrease

Answer 13

(1) More energy to pull an electron from a full d-subshell than the only electron in a p-subshell (same period)
(2) More energy to pull an electron from a full s-subshell than the only electron in a p-subshell (same period)
*Single electron is the only electron in the higher energy subshell, shielded by electrons in lower energy shells

Question 14

Why is second ionization potential greater than the first for an atom?

Answer 14

Removing the first electron decreases the radius, increases the ratio of protons to electrons

Question 15

Why does every element have one extremely large increase in ionization energy?

Answer 15

Electron configuration drops a principal quantum number.

Question 16

Electron affinity

Answer 16

How much an element wants to accept another electron

Question 17

Exothermic electron affinity

Answer 17

Negative releases energy
Wants to accept the electron
More negative, more it wants to accept the electron

Question 18

Endothermic electron affinity

Answer 18

Positive requires energy
Does not want to accept the electron

Question 19

When does electron affinity increase (values become more negative)?

Answer 19

Moving up a column, across a row

Question 20

Three characteristics of electron affinity moving down a group:
-Principal quantum number
-Shielding
-Coulomb’s law

Answer 20

-New shells, principal quantum number increases, larger orbitals
-Outer electrons experience a greater shielding effect and decreased effective nuclear charge
-Force of attraction decreases as atomic radius increases

Question 21

Why does group 2A have a positive electron affinity?
-Orbital
-Energy
-Shielding

Answer 21

-S-orbital is full
-Adding an electron would make it the only one in the higher energy p-orbital
-Shielding from inner core electrons is very high, energy must be added for them to accept another electron

Question 22

Why does group 8A have a positive electron affinity?
-Orbital
-Energy
-Shielding

Answer 22

-P-orbital is full
-Added electron would be the only one in the higher energy subshell
-Shielding from inner core electrons is very high, energy must be added for them to accept another electron

Question 23

Electronegativity

Answer 23

An elements ability to attract electrons in a chemical bond

Question 24

When does electronegativity increase?

Answer 24

Moving up a column, across a row

Question 25

Ionic Bonding

Answer 25

Cations and anions form electrostatic bonds based on opposite charges.

Question 26

Forming a bond is an ____ process, ____ energy

Answer 26

exothermic, releasing

Question 27

Breaking a bond is an ____ process, ____ energy

Answer 27

endothermic, requiring