Generally as compounds as iron oxides or iron sulfides.
it is found in metal chloride form.
It is a compound
Calcium is never found in its elemental form in nature.
In nature, titanium is always found as a compound, not as a pure metal. Titanium is highly reactive (although less reactive alloys can be made from it).
pure form
no
Both. Iron can be found by itself as a pure element, or it can be found in many compounds such as iron chloride, iron oxide, etc.
In pure form.
Technetium is found in both in a compound and pure forms
Usually it is found in compound form but can easily as a pure element, just depends on the conditions
in its pure form, iron is an element, but that may not be what you are referring to.... if you have iron oxide (rust), this is a compound of iron and oxygen.
Nickel is a metal. It can be found in a compound as a silicate or carbonate but in its pure form, it is neither. It has many characteristics similar to iron. It is magnetic like iron.
It is a compound
It is found in nature in its pure form (not as a compound).
Calcium is never found in its elemental form in nature.
In nature, titanium is always found as a compound, not as a pure metal. Titanium is highly reactive (although less reactive alloys can be made from it).
pure form
Iron can come in a pure metallic form but it is much more commonly found in non-metallic forms where it is combined with another element to make a compound. The most common are iron and oxygen in the forms of haematite and magnetite.