3.2 Periodic Trends

Which of the following best describes the trend in atomic size as you move from left to right across a period in the periodic table?

A. Increases steadily

B. Decreases steadily

C. Remains constant

D. First increases, then decreases

Which factor primarily affects the electronegativity of an element?

A. Number of electron shells

B. Number of valence electrons

C. Distance of valence electrons from the nucleus

D. Number of neutrons

Which of the following elements has the highest electronegativity?

A. Sodium

B. Chlorine

C. Iron

D. Neon

How does atomic size change as you move down a group in the periodic table?

A. Increases

B. Decreases

C. Remains constant

D. First decreases, then increases

Which of the following best describes the trend in ionisation energy as you move from left to right across a period?

A. Increases

B. Decreases

C. Remains constant

D. First decreases, then increases

a) Define atomic size and explain the factors that influence it. [3]

b) How does atomic size change as you move from left to right across a period in the periodic table? [2]

a) Define electronegativity and mention the scale commonly used to measure it. [2]

b) Describe the trend in electronegativity as you move down a group in the periodic table. [3]

a) What are transition metals, and how do they differ from main group elements in terms of their electron configuration? [3]

b) Why are many transition metals important catalysts in industrial processes? [2]

a) Describe the general trend in atomic size as you move from the top to the bottom of a group in the periodic table. [2]

b) Explain the underlying reason for this trend in atomic size. [3]

c) How does this trend affect the reactivity of alkali metals? [2]

a) Define ionisation energy and state its unit of measurement. [2]

b) Describe the trend in first ionisation energy as you move from left to right across a period. [3]

c) Explain the reason for the observed trend in part b. [2]