Question

12. An Element X has mass number 35 and neutron 18. Write atomic number
and electronic configuration of X. Also write group number and period
and find valency of X.
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Answer 1

Answer:

hope it may help you...

Answer 2

Answer:

element X have 35 mass number means it has the sum of electrons and neutrons =35, therefore

atomic number=35-18=17 protons

so the protons are 17 in the atom

Explanation:

its Electronic configuration will be =2,8,7

and the element with 17 electrons is chlorine (cl)

foun in 17 th group and 3 rs period of periodic table