Question

Which will be chemically more reactive element A with atomic no. 17 or element B with atomic no.16

Answer 1

element A will be more reactive than element B as both lies in third period of periodic table and when we go from left to right in a period reactivity increases. element A needs only one electron to complete its octate whereas element B needs two electron to complete its octate ,therefore element A will reactive than element B.

Answer 2

Explanation:

An element whose atomic number is 17 will need only one more electron in order to completely fill its octet. Thus, by gaining one electron it will become stable.

Whereas element whose atomic number is 16 will require two electrons in order to completely fill its octet. Thus, by gaining two electrons it will become stable.

Thus, we can conclude the element which requires only one electron to fill its octet will be more reactive. Hence, element A with atomic no. 17 is more reactive.