Halogens such as fluorine or chlorine are HIGHLY reactive; they always undergo chemical reactions with other elements to form compounds. It's almost impossible to find pure samples of any halogen gas.
Sodium is a highly reactive element. When it is in its pure form, it reacts with elements and moisture in the air almost immediately. It is more stable in compounds, so this is how it is found in nature.
Sodium
Minerals are naturally occurring inorganic substances with a specific chemical composition and crystalline structure. While they are primarily found in nature, some minerals can be synthesized in a laboratory setting to mimic their natural counterparts.
No.
Oxygen does not react more slowly than all of the halogens, just some of them. Plus, the rate of a reaction depends on its nature, not just whether oxygen or a halogen reacts. when the halogens do react faster, this is because they only need one electron to have a stable configuration, whereas oxygen needs two.
Halogens are found in nature primarily as salts, such as sodium chloride (table salt) or potassium iodide. They are highly reactive nonmetals that readily form ionic bonds with metals to create mineral salts.
Sodium is a highly reactive element. When it is in its pure form, it reacts with elements and moisture in the air almost immediately. It is more stable in compounds, so this is how it is found in nature.
Sodium
Helium is the only perfectly inert element, although there are several other inert elements which can be made to react with fluorine only with great difficulty, by the use of high temperature and pressure.
All the elements before neptunium are found in the nature. Also neptunium can be found in the nature only in ultratraces resulting from nuclear weapons experiments or other experiments.
Minerals are naturally occurring inorganic substances with a specific chemical composition and crystalline structure. While they are primarily found in nature, some minerals can be synthesized in a laboratory setting to mimic their natural counterparts.
No.
Berkelium is only an artificial element.
Phosphorus is a mineral. It can only be found in nature.
No.
Alkaline earth metals are found in nature only in mineral or compound forms, due to their high reactivity.
Not found in the nature, only in some specialized and rich laboratories.