List of top Science Questions on Structure of atom

An element 'M' has 25% of the electrons filled in the third shell as in the second shell. The element 'M' is :
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?