The elements most likely are halogens because if we talk about manner of bonding they all are diatomic molecules and need one electron to fill their outermost shell. That is why they bond with other atom of own type and exist as diatomic molecule in pure state. However, all halogens are so reactive that they react with metals through strongest type of ionic bonds and form salts.
They all tend to form salts when they react with metals like NaCl and that is why they are commonly known as salt dormers.
They perfectly show significant trends in some properties like atomic radius increases from top to bottom, boiling and melting temperature increase down the group and electronegativity value decrease from top to bottom.
The elements belong to group 17.
Hope it helps!
