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Related topics: Chemistry
con‧cen‧tra‧tion S3 W2
1 [uncountable] the ability to think about something carefully or for a long time [↪ concentrate]:
She needed all her powers of concentration to stop herself from slipping on the icy road.
Lack of concentration was a real problem.
I lost my concentration and fell asleep.
2 [uncountable] a process in which you put a lot of attention, energy etc into a particular activity [↪ concentrate]
concentration on (doing) something
concentration on your health
concentration on providing value and service
3 [uncountable and countable] a large amount of something in a particular place or among particular people [↪ concentrate]
concentration of
the concentration of greenhouse gases in the atmosphere
the concentration of power in the hands of a few
the effect on trees of high concentrations of sulphur dioxide around industrial areas
people with blood alcohol concentrations above the limit
4 [countable]HC technical the amount of a substance contained in a liquid [↪ concentrate]
high/low concentrations
Additives are expensive but are used in very low concentrations.
concentration of
allowable concentrations of pesticides in drinking water

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