The same as the "any key" on your keyboard - go ahead and choose any one.
Or, if this is what you mean, elements are defined by the number of protons in the nucleus.
Oxygen is an element and don'y contain any other element.
The center of an atom of any element is the nucleus.
Hydrogen is the only element without any neutrons.
I would expect Carbon to be the element that forms more compounds than any other element.
No. Kryptonite is a nobel gas, and doesn't react with any other elements.
All atoms of any single element have the same number of protons and electrons.
Any element that is in one of the representative elemenet groups is a representative element. A representative element group is any of the groups 1-2, 13-18, i.e. not a transition metal. So, a representative element is an element that isn't a transition metal.
The root is the core element of any medical term.
Every atom of one element has different no. of electrons than any atom of any other element.
Any element can be used to measure temperature.
an empty set does not have any element
Any chemical element; it is an error.