Answer the following question given this paragraph: 

Binary compounds are compounds composed of just two elements. The simplest kind of decomposition reaction is when a binary compound decomposes into its elements. Mercury(II) oxide, a red solid, decomposes when heated to produce mercury and oxygen gas.


Q: What are compounds composed of only two elements called?

 Choices:

- digital compounds

- symbiotic compounds

- kinetic compounds

- binary compounds

A:
binary compounds
