What is the product of the reaction of a Group 1 metal with oxygen?

The product of the reaction between a Group 1 metal and oxygen is a metal oxide, which corresponds to the selected answer. Group 1 metals, such as lithium, sodium, and potassium, are highly reactive and readily react with oxygen in the air. During this reaction, the metal reacts with oxygen to form a metal oxide. For instance, sodium reacts with oxygen to form sodium oxide (Na2O), while potassium reacts to form potassium oxide (K2O).

The reason why a metal oxide is formed is due to the nature of the Group 1 metals, which can easily lose their outermost electron to form stable ionic compounds. This characteristic facilitates their reaction with oxygen, where the oxygen gains electrons and is reduced to form the oxide anion (O^2−).

When considering the other choices, a metal chloride is formed when a metal reacts with chlorine rather than oxygen, a metal hydroxide typically forms when a metal reacts with water, and a metal carbonate results from a reaction involving carbon dioxide and a metal compound under certain conditions, usually not directly involving oxygen in the elemental state. Hence, the formation of a metal oxide is the definitive outcome of the reaction with oxygen, representing a fundamental behavior of Group 1 metals.