This video gives you a general idea on what chemistry is about.
This video gives a general explanation on what is matter & how does energy affects the changes in the states of matter.
Note: SPM chemistry syllabus only focus on the 3 states of matter: solid, liquid & gas. The 4th state of matter – plasma mentioned in this video, is not included in the SPM chemistry syllabus.
These videos explain the physical changes & chemical changes of matter.