particle – частица
layer – слой
top – вершина
effect – эффект
bottle – бутылка
salad dressing – приправа к салату
seasoning – приправа
oil – масло
to separate – отделять
to skim out – снять , отделить
to return – возвращаться
mixture – смесь
simply – просто
to shake up – встряхнуть
to disturb – нарушить, потревожить
Unique Properties
We can exploit the differences in substances' properties to allow separation. Consider these examples:
We can separate a mixture of sand and iron fillings by magnet.
We can separate salt and sand by solution (sand will not dissolve in water, salt will)
We can separate helium from a mixture with hydrogen by combustion (this is a very dangerous operation, since hydrogen in the presence of oxygen is highly explosive). Hydrogen is flammable, but helium is not.
There are countless other ways to separate mixtures. For instance, we use gel electrophoresis to separate different sized pieces of DNA. We place them into gel, and apply an electric current. The smaller pieces move faster and separate from the larger pieces.
Chromatography separates phases dissolved in liquid. If you want to see an example, take a strip of paper and draw a dot on it with a colored marker. Dip the strip into water, and wait for a while. You should see the ink separate into different colors as they spread out from the dot.
Vocabulary notes
difference – различие
substance – вещество
property – свойство
to exploit – использовать, эксплуатировать
to allow – допускать, представлять, позволять
separation – отделение
to consider – считать
mixture – смесь
sand – песок
iron – железо
filling – наполнение
to separate – отделять
magnet – магнит
salt – соль
solution – раствор
to dissolve – растворять
water – вода
helium – гелий
hydrogen – водород
combustion – горение
dangerous – опасный
operation – действие
presence – присутствие
oxygen – кислород
highly – сильно, высоко
explosive –взрывчатый
flammable – огнеопасный
countless – бессчетное множество
way – путь
gel electrophoresis – электрофорез с гелем
different – разный
size – размер
pieces of DNA – частицы ДНК
to place – помещать
electric current – электрический ток
to apply – применять
to move – двигать
fast – быстро
chromatography – хроматография
to dissolve – растворять
liquid – жидкость
strip – полоска
paper - бумага
to draw – чертить
dot – точка
colored marker – цветной маркер
to dip – опускать, погружать
wait for a while – подождать немного
ink – чернила
different colors – разные цвета
to spread out – распространяться
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