- Online Test Series
- Final Revision Module (3 Books)
- 5 Mock Tests
- 5 Diagnostic Tests
- 15 Practice Tests
- Sample Papers With Solutions
- Past Year Papers With Solutions
- Ask The Expert
- On Call Mentorship
Classification of Elements and Periodicity in Properties
Periodicity of Valence or Oxidation State
Example: Consider the two oxygen- containing compounds: OF2 and Na2O
The oxidation state of an element in a particular compound is the charge acquired by its atom on the basis of electronegative consideration from other atoms in the molecule.
Anomalous Properties of Second Period Elements
The first element of each of the Group 1 (lithium), Group 2 (beryllium) and Groups 13–17 (boron to fluorine) differs from the other members of their respective groups. Example: Lithium unlike other alkali metals and beryllium unlike other alkaline earth metals form compounds with pronounced covalent character.
The behaviour of lithium and beryllium is similar with the second element of the following group, i.e. magnesium and aluminium.
This type of similarity is known as diagonal relationship in periodic properties.
Different chemical behaviour of the first member of s-block and p-block: o The first member of a group of elements in the s-block and p-block shows different chemical behaviour to that of the subsequent members in the same group.
Periodic Trends and Chemical Reactivity
All chemical and physical properties are a manifestation of the electronic configuration of elements.
Variation in a period
Reaction with Oxygen
Variation in a Group
General Properties of Periodic Table
By learning in meritnation I got B2, but by learning topper learning I got A1... so which is the best. This is awesome to learn and easy to study science. At 1st term I got B2 but at 2nd term I got A1.
Manoj Vijay CBSE class IX
Excellent Faculty! I have been studying from topperlearning.com since Class IX and have consistently scored above 90% in my these 4 years.I studied throughout nights to achieve my goal.Moreover, becoming Rank 1 on topperlearning boosted my confidence to high skies.Thank you topperlearning, without you I would not have been able to score 91.2% in Class XII Boards(2015) and CGPA 9.8 in my Class X Boards(2013). Hope that topperlearning will continue to help students throughout India, creating a brighter future for them. Regards, Vivek Saahil
Vivek Saahil CBSE class XII Science
I like topper learning because I can understand the level I have prepared for my subject and study better.
Mohanapriya Saravanakumar CBSE class X
Topperlearning is really a very good helping tool. Every time I had doubts related to any concept in PCM I posted it and immediately my problem was solved. It also helped me in scoring good ranks in competitive exams too. The topper faculty is very good. The teachers explained each and every concept in depth. My favourite teacher is Physics teacher
Sahibdeep Singh Sodhi CBSE class XII Science
We all know that audio-visual medium is a better way of explaining and educating the students. It not only makes learning fun but also gives the message more clearly and precisely. Topper is a very good amalgamation of good teaching and good learning methods.
Sonia Malik, Professor
VV DAV School, New Delhi class ALL Class
Queries asked on Sunday and after 7 pm from Monday to Saturday will be answered after 12 pm the next working day.View More