Is Matter Around us Pure?
So purity is our guarantee. This milk is so pure. This water is very very pure. Why? Everything sold is being so pure. Right? Now but the word pure is being abused in one sense. So what do we really mean by pure? Or what do the scientists mean when they say something is pure? Now that’s a question, right? In fact the name of the chapter itself is ‘Is Matter Around us Pure?’ – A question for the name of the chapter. Isn’t it interesting? How many questions do we find as the name of the chapter? In order to answer that question though, we need to answer what matter is first. You know what matter is. So what’s the second thing we need to know to answer this question ‘Is Matter Around us Pure?’. What do you mean by pure? Without knowing what do we mean by pure, how can we say whether something is pure or not pure? Is something is pure if it looks very smooth? And I know if we take milk it looks pretty clean, pretty pure, it looks white all over. It looks pretty pure. So…but does that mean that milk is pure — in the sense of science? What do we need to know to answer that? What do we mean by pure? So then, what scientists mean when they say pure is that if you take that substance and if you put it somewhere- we know that it is made up of many many many small particles. Right? Really tiny ones. So what it means is that – if you pick a particle from any corner of the substance and some other corner you pick random particle, these two will be identical and no matter how many of the times you do this, no matter which particle you choose to pick. Because all these are going to be made up of small particles. In another words, if you ever played what’s called a play paint – there these large number of balls, you get to jump inside. It’s all plastic balls. Ya. You are allowed to go when you are a kid. And after a while you grow too tall and they don’t send you inside. Ya, you know what I mean. There is this little net around. So what makes up that entire place? A large number of little balls. Right? Now, if all the balls of the same colour—identical, then would it matter which place you put your hand inside and pick the ball? If they were all red. If there were a large number of red balls making up this place, you could put your hand anywhere, close your eyes, and pick one, you could be hundred percent sure that it is going to be a red colored ball. Now, if that is true, then if those kind of particles — identical ones — make up the substance, then it’s called pure. Makes some kind of sense. Doesn’t it? Then what is impure? It would obviously be that some of the balls are not identical. Right? So there are large numbers of red balls, insert some blue balls inside, then or some green balls, yellow balls– some other kind of substance, some other kind of particle, kind of _________ this–enters this. Then it’s impure. So what do we mean by pure? Every single particle that makes up the substance is the same–is identical.