Complete the statement.
Potassium bromide is ().

 - an elementary substance
 - a compound
You can tell whether potassium bromide is an elementary substance or a compound by counting the number of atomic symbols in its chemical formula. An atomic symbol consists of either one capital letter or a capital letter followed by one or two lowercase letters.
The chemical formula for potassium bromide, KBr, contains two atomic symbols: K for potassium and Br for bromine. So, the formula tells you that potassium bromide is composed of two chemical elements bonded together.
Since potassium bromide is composed of multiple chemical elements bonded together, potassium bromide is a compound.