____________is a polyatomic gas.
Hydrogen
Helium
Neon
Ozone
A mixture of carbon dioxide and oxygen can be separated by___________method.
___________are pure substances composed of two or more elements.
Atoms
Molecules
Compounds
Mixtures
In ________________method,the mixture of two gases passed through a flask placed in a freezing mixture.
The positively charged ions are called
Anions
Cations
____________is the smallest particle of a substance that can normally exist separately.
