Nobel gases are relatively nonreactive because they have eight electrons in the outermost energy level, which is a stable configuration
The boron family is moderately reactive. Boron itself is a relatively unreactive element, while the elements below it in the group, such as aluminum, can be more reactive due to their ability to form stable compounds with other elements.
The element is 'argon' and belongs to noble gas family.
In short, an element's valence shell is full and most stable when it contains eight electrons (this stability is the reason that the noble gases are so unreactive).
Noble Gasses.
Gold is a relatively unreactive solid metal because it doesn't easily corrode or tarnish in normal conditions. This property makes gold desirable for use in jewelry and other decorative items.
Copper is a naturally occurring element in its uncombined form because it is relatively stable due to its valence electron configuration. This stability decreases the likelihood of copper forming compounds with other elements. Additionally, copper is relatively unreactive in its pure form, further contributing to its presence as an uncombined element.
helium
Argon is the most unreactive in this series. Cheese is not an element; it is a mixture of compounds.
Krypton is an unreactive gas.
Balls
Inert.
Because helium is an unreactive chemical element.