Periodic Trends

Question 1

Atomic radius

Answer 1

Half the distance between 2 adjacent nuclei of an element in the solid phase

Question 2

Down a group, atomic radius

Answer 2

Increases

Question 3

Across a period atomic radius

Answer 3

Decrease

-more protons, pulls electrons in tighter

Question 4

While moving across a period, the tendency to lose an electron

Answer 4

DECREASES
bc. Atomic # (nuclear charge) increases
Shielding effect remains the same

Question 5

SHIELDING EFFECT

Answer 5

• weakened attractive force of the nucleus
• less attraction, farthest electron starts to drift
• INCREASE in atomic radius

Question 6

Metallic properties across a period

Answer 6

Decrease

Question 7

Metallic properties down a group

Answer 7

Increase

Question 8

First IONIZATION ENERGY

Answer 8

Amount of energy required to remove electron (atom on vapor phase)

Question 9

Across a period Ionization Energy

Answer 9

INCREASES
nuclear charge increases
shielding effect = constant

Question 10

Down a group Ionization Energy

Answer 10

DECREASES
occupied energy levels increase
nuclear charge canceled out by energy levels

Question 11

Ionic radii

Answer 11

Cations and anions

Ion- an atom with a charge

Question 12

Cations

Answer 12

Positive charge
Radii decreases: loosing electrons= getting smaller
Atomic radius > ionic radius

• 1 less occupied energy level
• more protons than electrons

Question 13

Anions

Answer 13

Negative charge
gaining electrons- gain negative charge
Atomic radius

Question 14

Electronegativity

Answer 14

Strength of attraction that an atom has for electrons

Question 15

Down a group, Electronegativity

Answer 15

DECREASES

increase in shielding effect (# occupied energy levels)

Question 16

Across a period, Electronegativity

Answer 16

INCREASES

Question 17

Atomic # (# of protons) across a period

Answer 17

DECREASES (nuclear charge)

Question 18

Electron affinity

Answer 18

Attraction of an atom for an electron

Question 19

Down a group electron affinity

Answer 19

DECREASES
(Metals have low electron affinities) losers
Release/gain small amounts of energy forming negative ions

Question 20

Across a period, electron affinity

Answer 20

INCREASES
(Nonmetals=high electron affinities)
Release a lot of heat to form negative ions

Question 21

Shielding effect is generally

Answer 21

Down a group

Question 22

Nuclear charge is generally

Answer 22

Across a period

Question 23

Across a period, valence electrons

Answer 23

Increase

Question 24

When moving across a period, ability to gain electrons

Answer 24

INCREASES

bc. Electronegativity (measured ability to attract electrons) increases

Question 25

Electronegativity within a period generally

Answer 25

Increases

Question 26

Principal energy levels across a PERIOD

Answer 26

Stays the same

bc. Shielding effect stays the same

Question 27

Down a group, tendency to lose electrons

Answer 27

INCREASES

Question 28

Up a group (decreasing atomic #) Electronegativity

Answer 28

INCREASES

decreases down a group

Question 29

Atomic # increases (#protons), ionization energy

Answer 29

DECREASES

Question 30

ELECTRONEGATIVITY vs ELECTRON AFFINITY

Answer 30

Electronegativity: relate measure by reacting things together

Electron Affinity: measured energy changes while gaining/ loosing electrons