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Question
Write the electronic configuration of two elements A and B whose atomic numbers are 20 and 17 respectively. Write the molecular formula of the compound formed when element A reacts with element B. State whether this compound is acidic, basic or neutral. Give a reason to justify your answer.
Solution
The electronic configuration of element A whose atomic number is 20 is 2,8,8,2 and the electronic configuration of element B whose atomic number is 17 is 2,8,7. The molecular formula of the compound formed when element A reacts with element B is AB2. The given compound is CaCl2 formed by the reaction of Ca(OH)2 (strong base) and HCl (strong acid). Since the reaction between a strong acid and a strong base yields a neutral salt so, CaCl2 is neutral.
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