A material that consists of only one type of element or compound.

Pure substance

Explanation:

A material that consists of only one type of element or compound is regarded as a pure substance.

A pure substance has the following properties;

All the parts are the same throughout i.e. they are homogenousThey have a definite composition. They cannot easily be separated or broken down into simpler substances by physical means. Separation by physical methods is not easyThey have unique sets of properties.

Compounds and elements are pure substances too.

The activity series is shown in the attached picture. if the element is below the other, then you can displace the other. following the activity series as a guide, the reactions are as follows: nickel and aluminum chloride3 ni + 2 alcl₃  → 3 nicl₂ + 2 albarium and copper bromideba + cubr  →  no reaction because cu is less oxidizable than bapotassium nitrate and aluminum3 kno₃ + al  → al(no₃)₃ + 3 ksodium phosphate and zincnaso₄ + zn  → znso₄ + na