Matter. We know that everything around us which has mass and occupies space is called matter. Bottle is a matter. Water is matter. Air is matter. Everything around as mostly called matter. We also know that everything that is matter is made up of very tiny particles. These tiny particles are called atoms and molecules. Till many centuries, it was known that anything that is matter is made up of very tiny particles which are indivisible. These are called atoms. Atoms were believed to be the smallest particle of matter which you cannot divide further. Let us go back to the 6th century where it all started. Around 500 BC, that is the 6th century, there was an Indian philosopher Maharishi Kannad. Now, I said philosopher because during that time, there were great personalities who used to lay down their philosophies and these philosophies proved to be very important for the modern day scientists. So, that time these personalities are known as philosophers. So, in 6th century there was a philosopher Maharishi Kannad. He was Indian. He was a Sanskrit teacher and he had many Sanskrit schools. One day, he was walking in a school with the rice grains in his hand. He chewed those rice grains and threw it back. Again, he chewed those rice grains and threw it back. He wanted to know how he can divide the rice grains into smaller smaller particles. He realized that, there comes a point that, the rice grains have been divided into such small particles which you cannot divide further. So, he told that everything that is matter is made up of tiny tiny particles. If you go on dividing matter, you will find that these tiny particles at one point of time cannot be divided further and he named these tiny indivisible particles as ‘Parmanu’. Parmanu is a Sanskrit word. So, according to Maharishi Kannad, everything that is matter and matter in Sanskrit is known as ‘Padarth’. So, everything that is Padarth is made up of individual particles called Parmanu. Around the same era, there were Greek philosophers Democritus and Leucippus. Democritus was a student of Leucippus. Both of them suggested that if we go on dividing anything that is matter, there comes a stage where we will find that the particles of matter are not further getting divided and Democritus call these individual particles atoms. Atom is a Greek word that means indivisible. All these were philosophically considerations and not much of experimental work was done to validate these philosophies till the 18th century. But by the end of 18th century, scientists could identify the difference between an element and a compound. They found out that elements chemically combined to form compound. They were very interested to know what happens during a chemical combination of elements. So, there was one of the scientists called Antoine Lavoisier. He was the first one to establish two laws of chemical combination.