• # question_answer An element P (atomic number 20) reacts with an element Q (atomic number 17) to form a compound. Answer the following questions giving reason: Write the position of P and Q in the Modern Periodic Table and the molecular formula of the compound formed when P reacts with Q.

 P = 20: 2, 8, 8, 2 Q =17: 2, 8, 7 P = Period 4 and Group 2 Q = Period 3 and Group 17 Hence formula of the compound formed between P and Q is $P{{Q}_{2}}$