List of top Science Questions on Structure of atom asked in Bihar Board X

The electronic configuration of an element is 2, 8, 7. What is the atomic number of the element?
The maximum number of electrons in a shell is:
How many bonds are there between two atoms in a molecule of nitrogen?
What is present in cathode rays?
What is present in cathode rays?
The electronic configuration of an element is 2,8,7. What is the atomic number of the element?