Complete the statement.
Graphite is ().
a compound an elementary substance
Graphite is used to make pencil lead. The chemical formula for graphite is C.
Every substance around you is made of one or more chemical elements, or types of atoms. Substances that are made of only one chemical element are elementary substances. Substances that are made of two or more chemical elements bonded together are compounds.
Every chemical element is represented by its own symbol. For some elements, the symbol is one capital letter. For other elements, the symbol is one capital letter and one lowercase letter. For example, the symbol for the element fluorine is F, and the symbol for the element beryllium is Be.
The symbol for each element in a substance is shown in the substance's chemical formula.
An elementary substance is represented by a chemical formula that contains only one symbol.
The symbol may be followed by a subscript. A subscript is text that is smaller and placed lower than the normal line of text. A subscript is included when the atoms in the elementary substance are bonded to form molecules. The subscript tells you the number of atoms in each molecule.
For example, the chemical formula for the elementary substance oxygen is O2. The formula has a subscript of 2. This subscript tells you that there are two atoms in the molecule represented by this chemical formula.
The chemical element represented by the symbol O is also called oxygen. So, the formula O2 tells you that each molecule of O2 contains two oxygen atoms.
A compound is represented by a chemical formula that contains multiple symbols.
For example, in the compound beryllium fluoride, there is one beryllium atom for every two fluorine atoms. This combination is shown in the compound's chemical formula, BeF2. In the formula, the symbol Be represents one beryllium atom. The symbol F followed by the subscript 2 represents two fluorine atoms.
You can tell whether graphite is an elementary substance or a compound by counting the number of symbols in its chemical formula. A symbol contains either one capital letter or a capital letter followed by one or two lowercase letters.
The chemical formula for graphite is C. This formula contains one symbol: C for carbon. So, the formula tells you that graphite is made of one chemical element.
Substances made of only one chemical element are elementary substances. So, graphite is an elementary substance.