Question

correctly describes what each of the substances is?
substance y is a compound and substance x and z are both mixtures
substance x is a compound, substance y is an element and substance z is a mixture
substance x and y are both compounds and substance z is a mixture
substance x and z are mixtures and substance y is a compound

Explanation:

• Substance X: It is made up of molecules that contain atoms of two different elements (A and B). According to the definition, a compound is a pure - substance formed when two or more different elements chemically combine in a fixed ratio. So, substance X is a compound.
• Substance Y: It is made up of molecules that contain only one type of atom (atom of element A). An element is a pure substance that cannot be broken down into simpler substances by chemical means. So, substance Y is an element.
• Substance Z: It contains two different types of molecules (one type with only A atoms and another type with only B atoms). A mixture is a combination of two or more substances (elements or compounds) that are not chemically combined. So, substance Z is a mixture.

Answer:

Substance X is a compound, substance Y is an element and substance Z is a mixture.