Номер 11, страница 179 - гдз по английскому языку 11 класс (enjoy english) учебник Биболетова, Бабушис

Appendix 2. What makes Chemistry fascinating? - номер 11, страница 179.

Условие.

11 Work in pairs. Arrange the instruction in the correct order.

How to Grow a Crystal?

Growing crystals starts with making a growing seed. For this, use a beaker or just a glass, pour hot water in it and dissolve the salt. Stir the solution. Add some more salt and stir it again. Keep adding the salt until it ceases to dissolve. When the salt does not dissolve any more, your solution has become saturated.

Do you know how to grow a crystal? It's not difficult but it takes time. In fact, a crystal or crystals can be grown from almost any salt, even from the table salt you use every day in your kitchen. But if you want to grow a nice looking blue crystal, take the copper sulfate.

When you decide that your crystal is big enough, pull it out of the beaker, and let your friends admire it.

Now pour the saturated solution back to the beaker and place the growing seed into it. To suspend the seed into the solution, tie the other end of a thread to a pencil and put it, horizontally, on the beaker. And leave the beaker alone!

Filter the saturated solution to make it pure (free of any unwanted particles) and leave the beaker for a few days. In a few days, you will see lots of crystals at the bottom of the beaker. Pour the solution into some bowl and choose the largest and the best looking crystal. Tie it to a thread or a fishing line, to make it look nicer. This is your growing seed.

The water from the solution will be evaporating and the crystal will be growing. Naturally, the level of the solution will be getting lower and to keep the crystal under the surface, you will have to add some more solution from time to time. Mind that the temperatures of the added solution and the solution your crystal is growing in should be the same. Don't add a hot solution! In this case your crystal may be damaged! And another tip — filter the solution from time to time to prevent different impurities to stick to your crystal. They may cause forming new crystals and spoil the original one.

If you want to perform this experiment at home, mind the safety rules. Copper sulfate is moderately toxic, avoid skin and eye contact with the salt and the solution. It's recommended to wear protective gloves and goggles. If the copper sulfate (the salt or the solution) gets into your eyes, flash them with lots of water and consult the doctor.

Решение.

Решение 2.

11 Работа в парах. Расположите инструкцию в правильном порядке.

Ответ:

The correct order of the paragraphs is: 2, 7, 1, 5, 4, 6, 3.

Правильный порядок абзацев: 2, 7, 1, 5, 4, 6, 3.