Periodic Trends: Ionization Energy and Electronegativity

Periodic Trends: Ionization Energy and Electronegativity

Bromfield Honors Chemistry

Multiple Choice

What is a negative ion called?

• anion

• cation

• covalent

• isotope

Multiple Choice

What is a positive ion called?

• anion

• cation

• isotope

• covalent

​Ionization energy

​​A + IE ⟶ A⁺ + e^-

​Ionization energy

​The energy required to remove the outermost electron from an isolated gas phase atom

​Ionization energy

Multiple Choice

Ionization energy corresponds to the ...

• energy required to add an electron to an atom

• energy required to remove an electron from an atom

• energy required to shield the outer electrons from the nucleus

• a measure of the ability of an atom to attract electrons

Multiple Choice

What type of element typically loses electrons?

• metals

• nonmetals

• metalloids

• noble gases

Metals typically lose electrons to form cations

​

What kinds of elements typically lose electrons?

​

Fill in the Blank

What type of elements typically gain electrons?

Nonmetals don't usually LOSE electrons

Nonmetals typically gain electrons to form anions

​

As you go from left to right across a period, IE typically INCREASES

​IE period trend

As you go from left to right across a period, IE typically INCREASES

​Why?

As the nuclear charge increases, there is a stronger Coulombic attraction between the valence electron and the nucleus​

The outermost electrons are occupying the same energy level​

​IE period trend

As you go down a group, IE typically DECREASES

​IE group trend

As you go down a group, IE typically DECREASES

​Why?

As you go down a column, the outermost electrons are occupying additional energy levels

Because the valence electrons are farther from the nucleus, they have a weaker Coulombic attraction to the nucleus

​IE group trend

Multiple Choice

Ionization energy __________ as you go L to R across a period

• has no pattern

• stays the same

• decreases

• increases

Fill in the Blank

Ionization energy __________ as you go down a group.

Multiple Choice

Which element has the higher ionization energy?

• Magnesium (Mg)

• Phosphorus (P)

Multiple Choice

Which element has the higher ionization energy?

• Iodine (I)

• Chlorine (Cl)

Multiple Choice

Francium (Fr) has the lowest ionization energy in Group 1 because ___. 

• it has the smallest number of valence electrons
• it has the greatest atomic mass
• it has the greatest number of protons, so it attracts its electrons the strongest
• its 1 valence electron is very far from the nucleus, so little energy is needed to remove the electron

Multiple Choice

Which of the following elements would have the lowest ionization energy?

• K

• P

• S

• Ca

• Mg

Multiple Choice

Which of the following would have the largest ionization energy?

• Na

• Al

• Mn

• N

• Pd

​Electronegativity

​The tendency of an atom, when interacting with other atoms, to attract electrons to itself

​F

Most electronegative element

​Cs & Fr

Least electronegative element

Electronegativity INCREASES as you left to right across a period

Period trend

Electronegativity DECREASES down a column

​

Group trend

Fill in the Blank

Electronegativity _________ as you go down a group.

Multiple Choice

Which element has a lower electronegativity value?

• Calcium

• Barium

Multiple Choice

Which element has the greater electronegativity?

• Si

• Cl

Multiple Choice

Rank these elements in increasing order of electronegativity:

F, N, B

• B < N < F
• B < F < N
• N < F < B
• F < N < B

Multiple Choice

Which has the greater electronegativity: S, Al, or Ga?

• S

• Al

• Ga

Multiple Choice

Which of the following is the least electronegative element?

• oxygen
• strontium

• fluorine
• carbon

Multiple Select

Which of the following elements has a lower electronegativity than Al?

(Select all that apply)

• C

• Mg

• In

• O

• P

Multiple Choice

What is the trend for EN as you move down a group or family and why?

• EN increases because the number of energy levels decreases, causing a stronger Coulombic attraction between the valence electron and the nucleus

• EN decreases because the number of energy levels increases, causing a weaker Coulombic attraction between the valence electron and the nucleus

• EN increases because the number of energy levels increases, causing a stronger Coulombic attraction between the valence electron and the nucleus

• EN decreases because the number of energy levels decreases, causing a stronger Coulombic attraction between the valence electron and the nucleus

Multiple Choice

Rank the following elements in order of increasing electronegativity:

Se, S, and O

• Se < S < O
• Se < O < S
• O < S < Se
• S < Se < O

Multiple Choice

As you look from left to right across a period, ionization energy and electronegativity both

• increase

• decrease

Open Ended

Write a brief summary of the key points from today's class: