Since early times, human beings have been trying to understand their surroundings. Early Indian philosophers classified matter in the form of five basic elements – the “Panch Tatva”– air, earth, fire, sky and water.
For a long time, two schools of thought prevailed regarding the nature of matter. One school believed matter to be continuous like a block of wood, whereas, the other thought that matter was made up of particles like sand.
Activity ______________ 1.2
• Take 2-3 crystals of potassium permanganate and dissolve them in 100 mL of water. Take out approximately 10 mL of this solution and put it into 90 mL of clear water.
• Take out 10 mL of this solution and put it into another 90 mL of clear water.
• Keep diluting the solution like this 5 to 8 times.
• Is the water still coloured?
In Potassium permanganate (KMnO4) we can conclude there must be millions of tiny particles in just one crystal of it.
As the temperature rises, particles move faster. So, we can say that with increase in temperature the kinetic energy of the particles also increases
KINETIC ENERGY
The energy possessed by an object in motion is called kinetic energy
Matter around us exist in three different states – solid, liquid and gas.
PHYSICAL PROPERTIES OF MATTER
SOLID LIQUID GAS
CHEMICAL PROPERTIES OF MATTER
ELEMENTS MOLECULES COMPOUNDS
SOLID STATE
We
can observe that all these have a definite shape, distinct boundaries and fixed volumes, that is, have negligible compressibility. Solids have a tendency to maintain their shape when subjected to outside force. Solids may break under force but it is difficult to change their shape, so they are rigid
LIQUID STATE
Liquids have no fixed shape but have a fixed volume. They take up the shape of the container in which they are kept. Liquids flow and change shape, so they are not rigid but can be called fluid
GASEOUS STATE
-------------------------------------------------