Quick answer: The modern periodic law states that the physical and chemical properties of elements are periodic functions of their atomic numbers. Increasing atomic number produces recurring valence-shell configurations, which explains the structure of groups and periods. Electronic configuration therefore determines an element’s block, position, typical valency and many periodic properties.
What you will learn
- Statement and meaning of modern periodic law
- Long form of the modern periodic table
- Groups, periods and s, p, d and f blocks
- Finding position from electronic configuration
- Connections with periodic trends
Important questions answered
What is the modern periodic law?
The properties of elements are periodic functions of their atomic numbers.
Why is atomic number used instead of atomic mass?
Atomic number represents nuclear charge and determines electronic configuration, which directly controls chemical behaviour.
How does electronic configuration locate an element?
The highest principal shell gives the period, while the valence configuration helps identify the group and block.
Who should use this lesson?
This lesson is useful for school students, competitive-exam aspirants, parents supporting a learner and teachers looking for a clear explanation. Watch the complete video, make short notes and then practise the ideas without looking at the solution.
Learn with Lalit Kumar Mishra
Lalit Kumar Mishra is a chemistry educator, student success mentor, author and Founder of Topper Formula, with more than 20 years of teaching experience. Explore more learning and mentoring resources on the Resources page.