Question

Which pair of elements would most likely have a similar arrangement of outer

electrons and have similar chemical behaviors?
boron and aluminum
helium and fluorine
carbon and nitrogen
chlorine and oxygen

Answer 1

Boron and Aluminum

Step-by-step explanation:

If you write the electron configuration for boron and aluminum, you get:

`1s^22s^22p^1` for boron and
`1s^22s^22p^63s^23p^1` for aluminum. Both have 3 valance electrons and has 2 electrons in a s-orbital and 1 in a p-orbital. These valance electron similarities are based on the column/group the elements are. Therefore, Boron and Aluminum have similar chemical behaviours and similar arrangement of outer/valance electrons.