Question
The atomic numbers of three elements $A, B$ and $C$ are given below:
| Element | Atomic Number |
| $A$ | $5$ |
| $B$ | $7$ |
| $C$ | $10$ |
- Which element belongs to group $18?$
- Which element belongs to group $15?$
- Which element belongs to group $13?$
- To which period/ periods do these elements belong$?$
