elements, compounds and mixtures

Question 1

what are elements?

Answer 1

elements are pure substances that cannot be split up into two or more simpler substances by chemical methods
they consist of 1 type of atom
they have a fixed melting and boiling point

Question 2

what are compounds?

Answer 2

compounds are pure substances that contain two or more elements chemically combined in a fixed ratio

Question 3

what are mixtures?

Answer 3

mixtures consist of two or more substances not chemically combined together. some examples are air, salt solution, alloy(steel)

Question 4

what is difference between compounds and mixtures in terms of…
separation
composition
melting and boiling point

Answer 4

-compounds are broken down by chemical means, whereas mixtures are separated by physical means
-compounds have a fixed composition, whereas mixtures do not have a fixed composition
-compounds have a fixed melting and boiling point, whereas mixtures do not have a fixed melting and boiling point