For a long time, explaining how to mix the concentrated sulfuric acid with water, teachers forced pupils to remember the rule: "At first water, then – acid!" The fact is that if to arrive on the contrary, the first portions of more light water which appeared above literally "will boil" as at this mixing a large amount of warmth is distinguished - splashes will scatter extensively. How after all to mix reagents?
The earth is the amazing planet. Its climatic zones are various, and variety of the natural phenomena - some the person is still not capable not only to prevent, but to predict at least – do it unique. Among other, time of catastrophic events, a change of seasons – the phenomenon constant, habitual and expected. Why and how there is a change of seasons?
