Very common - sodium is found in table salt, for instance.
Zinc is a common element.
Element
Sodium chloride(NaCl),common salt.
It is classified as a rare earth element.
Sodium is found in many common materials. The best example is Common Salt( NaCl).
Sodium
is the element boron abundant or rare on earth
The element most common in tothpaste is sodium.
It is a compound: NaCl-sodium [an element] bonded to chloride [an element].
Sodium which forms sodium chloride or common salt
Promethium is a rare artificial element.
Sodium itself is an element, not a compound. If you are talking about dietary sodium, the most common source that to get that from is the compound sodium chloride (salt).