Group the following electron configurations in pairs that would represent elements with similar chemical properties.

a. 1s22s22p5
b. 1s22s1
c. 1s22s22p6
d. 1s22s22p63s23p5
e. 1s22s22p63s23p64s1
f. 1s22s22p63s23p64s23d104p6

1. (a) and (b)
2. (a) and (c)
3. (a) and (d)
4. (a) and (e)
5. (a) and (f)
6. (b) and (c)
7. (b) and (d)
8. (b) and (e)
9. (b) and (f)
10 (c) and (d)
11. (c) and (e)
12. (c) and (f)
13. (d) and (e)
14. (d) and (f)
15. (e) and (f)