Which of these is a mixture? oxygen, air, sugar or common salt

The modern periodic table has groups.

When the volume and number of particles of a gas are constant which of the following is also constant

This flow chart shows the amount of energy that is emitted by each type of light. ultraviolet > blue light > yellow light > red light (maximum energy) (minimum energy) in an experiment, shining which type of light on a strip of metal would be least likely to produce the photoelectric effect? ultraviolet light dim blue light bright red light bright yellow light