Oxygen is composed of only one kind of atom and can’t be separated into simpler substances. what type of matter is it?

solution

element

mixture

compound

colloid

Element

Explanation:

When atoms can't be chemically separated into simpler substances, they are an element.

Alternatively: Oxygen can be found in the Periodic Table of Elements. Thus, it is an element.

All the other options (solution, mixture, compound and colloid) refer to different way in which two or more substances (be it elements or molecules) are together.

on passing the small ampere of electric current through the tube made of ar and hg of cfl generates uv rays which excites the fluorescent and thus emits the high radiation by consumption of just 5- 12 w in comparison to incandescent light which requires more power such as around 40 - 55 w to lighten.

moreover the life span of fluorescent or cfl is around 8000 h whereas the life span of incandescent is around 1200 h

hence, the building installed with incandescent lights bears more electricity bill.