Dear Students ,if you get something from my blog then share it,to help other students...........Thanks..

Properties of Matter

Every substance has characteristic properties. These properties can be classified into 2 categories: - Physical and Chemical properties.

Physical properties

They are those properties which can be measured or observed without changing the identity or the composition of the substance.
Some examples of physical properties are colour, odour, melting point, boiling point, density etc.

Chemical properties

The chemical properties require a chemical change to occur.
Chemical properties are characteristic reactions of different substances; these include acidity or basicity, combustibility etc.
The International System of Units (SI)
- The International System of Units (in French Le Systeme International d’Unités – abbreviated as SI) was established by the 11th General Conference on Weights and Measures.
- The SI system has seven base units and they are listed in figure below. These units pertain to the seven fundamental scientific quantities.
- The other physical quantities such as speed, volume, density etc. can be derived from these quantities.
Base Physical Quantities and their Units

Definitions of SI Base Units

Problem:-

Convert the following into basic units:

(i) 28.7 pm

(ii) 15.15 pm

(iii) 25365 mg

Problem:-

If the speed of light is 3.0 ×108 m s-1, calculate the distance covered by light in 2.00 ns.
Mass & Weight
- Mass is defined as the amount of matter present in a substance.
- Weight is defined as the force exerted by the gravity on an object.
- The mass of a substance is constant whereas its weight may vary from one place to another due to change in gravity.
- The mass of a substance can be determined very accurately in the laboratory by using an analytical balance.
- The SI unit of mass is kilogram.