Question

Define a) pure substances b) elements c) compounds d) metals e)non-metals,metalloids and mixture

Answer 1

a substance which is made up of only one kind of particle is called a pure substance

An element is a substance that is made entirely from one type of atom. For example, the elementhydrogen is made from atoms containing a single proton and a single electron. If you change the number of protons an atom has, you change the type of element it is.

A compound is a substance formed when two or more chemical elements are chemically bonded together.

A group of elements in the periodic table is called metals. 

Nonmetal or non-metal is a chemical element that does not have the properties of a metal. They can either begases or elements that do not look like metals.

A metalloid is any chemical element which has properties in between those of metalsand nonmetals, or that has a mixture of them. There is neither a standard definition of a metalloid nor complete agreement on the elements appropriately classified as such. 

a substance which is consist of 2 or more kind of particles is called a mixture

Answer 2

pure substances - A pure substance is made up of one kind of molecules........ All elements and compound are pure substances.

elements - It is a pure substance consisting of same type of atoms...

compound - A substance that consists of teo or more element combined together in definite proportions is called compound

metals- Metals are usually shiny, hard, malleable, and ductile and are good conductor of electricity... Ex_ copper, iron etc

non metals - Non metals are dull, non lustrous and brittle and do not reflect light
eg - carbo, oxygen etc

metalloids- These are the elements, intermediate in properties between metal and non-metals ..... eg - Boron, silicon etc

mixture- Mixture is obtained when two or mord substances mixed together in such a way that they do not lose their own properties
eg water vapours