Classify each of the following pure substances as an element or a compound:
d. rust (Fe₂O₃)

Verified step by step guidance

1. Identify the chemical formula of the substance provided. In this case, the formula is Fe₂O₃.
2. Analyze the formula to determine if it consists of only one type of atom or multiple types of atoms. Fe₂O₃ contains two different elements: iron (Fe) and oxygen (O).
3. Recall the definition of an element: a pure substance that consists of only one type of atom. Since Fe₂O₃ contains more than one type of atom, it cannot be classified as an element.
4. Recall the definition of a compound: a pure substance formed when two or more different elements are chemically bonded together in a fixed ratio. Fe₂O₃ fits this definition because it is composed of iron and oxygen atoms chemically bonded in a 2:3 ratio.
5. Classify rust (Fe₂O₃) as a compound based on the analysis above.

Key Concepts

Element

An element is a pure substance that cannot be broken down into simpler substances by chemical means. It consists of only one type of atom and is represented on the periodic table. Examples include hydrogen (H), oxygen (O), and iron (Fe). Elements are the fundamental building blocks of matter.

Compound

A compound is a pure substance formed when two or more different elements chemically bond together in fixed proportions. Compounds have unique properties that differ from the individual elements that compose them. For example, water (H₂O) is a compound made from hydrogen and oxygen, while rust (Fe₂O₃) is a compound formed from iron and oxygen.

Chemical Formula

A chemical formula is a symbolic representation of a compound that indicates the types and numbers of atoms present. For instance, the formula for rust, Fe₂O₃, shows that it contains two iron (Fe) atoms and three oxygen (O) atoms. Understanding chemical formulas is essential for identifying whether a substance is an element or a compound.