Pg:- 7,8
Ch:- 1
A pure substance is a material that consists of only one type of particle, meaning it has a uniform and definite composition throughout. This can be an element or a compound.
Pure substances have specific melting and boiling points, which are used to identify and distinguish them from mixtures.
Every sample of a pure substance has the same physical and chemical properties.
It is uniform in composition; the properties are the same regardless of where you sample it within the substance.
Elements are the simplest pure substances that cannot be broken down into simpler substances by chemical means. Examples include oxygen (O₂), gold (Au), and hydrogen (H₂).
Compounds are pure substances formed when two or more elements chemically combine in fixed ratios. Examples include water (H₂O), carbon dioxide (CO₂), and sodium chloride (NaCl).
1.Can a pure substance be separated into other substances by physical means?
2.What are some examples of pure substances?
3.Why is it important to use pure substances in chemical reactions?
4.How do impurities affect the properties of a substance?
5. what is the significance of purity in pharmaceutical industry?