Question

An element x has mass number 35 and neutrons is 18.identify the group number and period of x

Answer 1

Mass no. =neutrons + electrons
35=18+electrons
Electrons =17
Now,
Element X is chlorine (2,8,7)
Group no. = 17th group as there are 7 valence electrons
Period no =3rd period as there are 3 shells

Answer 2

mass no. =35
neutron =18
mass no. =neutron +electon
35=18+x
x = 35-18
x= 17

E. C = 1s²,2s²2p6,3s²3p5
group no. = 17t
period no. = 3

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