Class 10 Chemistry Chapter 1
Periodic Properties and Variations of Properties
Important Questions

In ICSE Class 10 Chemistry Chapter 1, titled “Periodic Properties and Variations of Properties,” elements found in the same groups, which are the vertical columns of the periodic table, demonstrate similar chemical characteristics. This uniformity is a result of group members having identical numbers and arrangements of electrons in their outermost electron shells. However, there are additional recurring patterns in chemical properties observed across the periodic table, including chemistry important questions class 10 ICSE.
‍For instance, as one moves down a group, the metallic properties of atoms become more pronounced. To illustrate, in the uppermost position of group 16 (6A), oxygen exists as a colourless gas. In the middle of the group, selenium takes the form of a semi-conductive solid. Meanwhile, towards the lower end of the group, polonium appears as a silver-grey solid with electrical conductivity. These observations are essential when preparing for ICSE Class 10 Chemistry important questions.
Conversely, when traversing a period from left to right, each successive element involves the addition of a proton to the nucleus and an electron to the valence shell. In contrast, while moving down a group, the count of electrons within the valence shell remains constant, but the principal quantum number increases by one with each step.
Understanding the electronic configuration of elements empowers us to analyse specific properties that dictate their chemical behaviour. These properties exhibit periodic variations as the electronic configuration of elements changes. These properties encompass factors such as the size (radius) of atoms and ions, ionisation energies, and (3) electron affinities. These concepts are crucial when studying ICSE Class 10 chemistry important questions.