Explanation:
Firstly, we need to define a mixture, compound, and element
Mixture: A mixture is defined as a substance that contains two or more constituents that are physically combined together.
Compound: A compound is defined as a substance that contains two or more elements that are chemically combined together.
Element: An element is defined as a substance that cannot be split into simpler units by an ordinary chemical reaction.
The next thing is to group the various substance into the mixture, compound, and element
Helium ----------- Element
Vinegar -------- Compound
Iron ------------ Element
Methane ----- compound
Coffee ------- Mixture
Dry -ice ------- compound
Table sugar ---- Compound