"तत्वों के भौतिक और रासायनिक गुण उनके परमाणु भारों के आवर्त फलन होते हैं", यह नियम किसने दिया था?

The correct order of increasing metallic character of Na, Be, P, Mg and Si is:

Which of the following is the correct order of increasing atomic radii for nitrogen, oxygen, and fluorine?

Which of the following represents the correct increasing order of atomic radii for the elements fluorine (F), oxygen (O), and nitrogen (N)?