Trends in the periodic table Gr 11 Chem

Question 1

Atomic Radius increase/decrease

Answer 1

Across a Period (→): Decreases

More protons in the nucleus pull electrons in tighter.
Electrons are added to the same energy level, so no extra shielding.
Down a Group (↓): Increases

More energy levels (shells) are added, making the atom larger.
Shielding effect reduces the pull of the nucleus.

Question 2

First Ionization Energy increase/decrease

Answer 2

Across a Period (→): Increases

More protons = stronger nuclear pull = harder to remove an electron.
Atoms on the right (like Fluorine) want to keep their electrons to stay stable.
Down a Group (↓): Decreases

Outer electrons are farther from the nucleus (more shielding), so it’s easier to remove them.

Question 3

Electron Affinity increase/decrease

Answer 3

Across a Period (→): More Negative (Increases in Magnitude)

Atoms on the right (especially nonmetals) want electrons to complete their octet.
Noble gases are an exception; they have low electron affinity because they’re already stable.
Down a Group (↓): Becomes Less Negative (Decreases in Magnitude)

Larger atoms don’t attract extra electrons as strongly due to shielding.

Question 4

Electronegativity increase/decrease

Answer 4

Across a Period (→): Increases

Nonmetals (right side) want electrons more than metals.
Fluorine (most electronegative) is the best at attracting electrons.
Down a Group (↓): Decreases

Atoms get larger, so the nucleus has a weaker pull on bonding electrons.

Question 5

What is First Ionization Energy

Answer 5

(Energy needed to remove 1 electron)

Question 6

What is Electron Affinity

Answer 6

(Energy change when an atom gains an electron)

Question 7

What is Electronegativity

Answer 7

(Ability to attract electrons in a bond)