Answer :
Sugar : Compound
Air : Homogeneous mixture
Hot tea : Homogeneous mixture
Salt water : Homogeneous mixture
Explanation :
Element : It is a pure substance which is composed of atoms of similar elements.
Compound : It is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.
Heterogeneous mixtures : It is a mixture that has non-uniform composition throughout the solution and the particle size or shapes are also different.
There is a physical boundary between the dispersed phase and dispersion medium.
Homogeneous mixtures : It is a mixture that has uniform composition throughout the solution and the particle size or shapes are not different.
There is no physical boundary between the dispersed phase and dispersion medium.
As per question,
Sugar : It is a compound that is made from atoms of different elements combined together in a fixed ratio by mass.
Air : It is a homogeneous mixture of the gaseous substances of nitrogen, oxygen, and smaller amounts of other substances.
Hot tea : It is a homogeneous mixture because its composition is the same throughout the solution.
Salt water : It is a homogeneous mixture because its composition is the same throughout the solution.