What do the metals calcium, magnesium, sodium, potassium, copper, and iron have in common?

Expert Answers
trophyhunter1 eNotes educator| Certified Educator

Every one of these elements can react with oxygen to form an oxide or if oxygen and water are present, a hydroxide. For example, iron and oxygen chemically combine to form rust, or iron oxide. Sodium will burn in oxygen to form sodium peroxide. Because all metals to an extent will react with oxygen, most are not found in a pure state in nature, rather, they are found in a compound usuallly as an oxide. When a copper structure like a statue, or when found as an architectural element on a building is seen, it is usually green due to the fact that you are looking at copper oxide. Therefore, the answer is that all of the elements react with oxygen.