Which electron configurations represent the first two elements in Group 17 (7A) of the Periodic Table?
A
1s22s1 and 1s22s2

B
1s22s22p6 and [Ne]3s23p5

C
1s22s22p5 and [Ne]3s23p5

D
1s22s2 and 1s22s22p1

Option C is correct

1s22s22p5 and [Ne]3s23p5

Explanation:

Step 1: Data given

Group 17 = the halogens

Halogens have 7 valence electrons

The first element of group 17 = Fluorine (F)

Fluorine has 9 electrons

The electron configuration is

1s2 2s2 2p5

The second element of group 17 = Chlorine (Cl)

Chlorine has 17 electrons

The electron configuration is

1s2 2s2 2p6 3s2 3p5

Option C is correct

1s22s22p5 and [Ne]3s23p5

um i think it might be a car?

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.