Well you can demonstrate matter and its properties by using a small object, for instance take a chalk. Tell them that everything that exists is one or another form of the matter. This chalk also contains matter. It can neither be created nor destroyed. Then you ask your class mates if they think against this property of matter. If they say that they can destroy this chalk, ask them to do so. Or you can break the chalk in to smaller pieces yourself. Then you can tell them that look, even if we grind this chalk, make so small pieces out of it, still we wont be able to destroy it. It will only change its shape, it will only get converted to small particles, but it will always exist in one form or another, because this is what you call "matter".
You can also use the example of Wood. Break in into pieces, or burn it to ashes. Still it will not be destroyed. The less weight of the ashes that the wood itself in fact suggest that the matter has changed its form from solid (wood) to solid (ashes) and gas (smoke).
You can also use the example of Wood. Break in into pieces, or burn it to ashes. Still it will not be destroyed. The less weight of the ashes that the wood itself in fact suggest that the matter has changed its form from solid (wood) to solid (ashes) and gas (smoke).
