Question 1

What is periodicity in the context of the periodic table?

Accepted Answer

Periodicity refers to the recurring trends that are observed in the properties of elements as you move across the periodic table. These trends arise due to the arrangement of electrons in atoms and the periodic nature of the elements' atomic structure. Understanding periodicity helps predict the chemical behavior of elements, which is a key concept in IB DP Chemistry.

Question 2

How does atomic radius change across a period and down a group?

Accepted Answer

As you move across a period from left to right, the atomic radius generally decreases. This is because the number of protons increases, leading to a stronger attraction between the nucleus and the electrons, pulling them closer. Conversely, as you move down a group, the atomic radius increases due to the addition of electron shells, which outweighs the increase in nuclear charge.

Question 3

What is the trend in ionization energy across a period and down a group?

Accepted Answer

Ionization energy tends to increase across a period from left to right because the increasing nuclear charge makes it more difficult to remove an electron. However, ionization energy decreases down a group as the outer electrons are further from the nucleus and are more easily removed due to increased electron shielding.

Question 4

How does electronegativity vary across the periodic table?

Accepted Answer

Electronegativity increases across a period from left to right due to the increasing nuclear charge, which attracts electrons more strongly. It decreases down a group as the additional electron shells reduce the nucleus's pull on the valence electrons. This trend is crucial for understanding chemical bonding in IB DP Chemistry.

Question 5

What is the significance of periodicity in predicting chemical reactions?

Accepted Answer

Periodicity allows chemists to predict how elements will react with each other based on their position in the periodic table. Elements with similar periodic properties often exhibit similar chemical behaviors. This predictive power is essential for understanding and anticipating the outcomes of chemical reactions, a fundamental aspect of the IB DP Chemistry curriculum.

Periodicity

Short Notes - Periodicity

Study Notes & Exam Tips

Periodicity — frequently asked questions