English version

concentration in Chemistry topic

From Longman Dictionary of Contemporary Englishconcentrationcon‧cen‧tra‧tion /ˌkɒnsənˈtreɪʃən $ ˌkɑːn-/ ●●● S3 W2 AWL noun  1 [uncountable]THINK ABOUT the ability to think about something carefully or for a long timeconcentrate 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]ATTENTION a process in which you put a lot of attention, energy etc into a particular activityconcentrateconcentration on (doing) something concentration on your health concentration on providing value and service3 [countable, uncountable]AMOUNT a large amount of something in a particular place or among particular peopleconcentrateconcentration of the concentration of greenhouse gases in the atmosphere the concentration of power in the hands of a few4 [countable]HCLIQUID technical the amount of a substance contained in a liquidconcentratehigh/low concentrations Additives are expensive but are used in very low concentrations.concentration of allowable concentrations of pesticides in drinking waterCOLLOCATIONSverbssomething takes concentration (=needs concentration)Playing a musical instrument takes a lot of concentration.something requires/demands concentration formalWriting an exam requires great concentration.lose (your) concentrationHalfway through the game, he seemed to lose concentration.break somebody’s concentration (=stop someone concentrating)The telephone rang and broke my concentration.disturb somebody’s concentrationShe slipped out of the room, trying not to disturb his concentration.phrasessomebody’s powers of concentration (=someone’s ability to concentrate hard)Great athletes are known for their powers of concentration.a lack of concentrationA lack of concentration when you are driving can be fatal.a lapse in/of concentration (=a short time when you do not concentrate)That brief lapse of concentration resulted in a goal for the other team.adjectivesgreat/deep concentrationMy work demands great concentration.poor concentrationThe boy had behavioural problems and suffered from poor concentration.total concentrationI was impressed by her total concentration on the game.intense concentration (=very great concentration)The job demands intense concentration.concentration + NOUNa concentration span (=the length of time that you are able to concentrate)Young children have a short concentration span.
Examples from the Corpus
concentrationIt was only later that the aesthetic dimension of literary study became emphasized, with an accompanying concentration on the fictional genres.Plummer said she plans to continue her concentration on the 3,000 meter race.A lack of response would suggest that the high concentration of alcohol is the principal factor.Used in the right concentrations, they colour hair for up to six washes and add a protective film.The result is that the concentration of neurotransmitters in a synapse increases and the normal actions of the neurotransmitter is enhanced.So, supposing I tried, the task would demand total concentration.His face was solemn with concentration.A good night's sleep will improve your concentration.lost ... concentrationThey were also tired and when Bath turned again to the Campese option an important part of the Gloucester defence lost concentration.This inability to translate pressure into points seemed to erode their tenacity and the forwards, in particular, lost concentration.Even the best sentry lost concentration.Once, for an instant, she lost her concentration and a smile cracked across her features.She lost concentration, and the pygmy vanished.They lost concentration at times with a big lead behind them.Worst of all the defence totally lost concentration after about eighty five minutes gone.concentration on (doing) somethingThe effect of Ca 2+ concentration on the calmodulin modulation of channel activity was also measured using the neutral red dye assay.The influence of lavage was evaluated by comparing the corresponding concentrations on both days.He returned to assist Frye, who was standing now with a frown of concentration on his face.One is Dyck's concentration on systems of generators for a group and on relations satisfied by these generators.He was kneeling in sober concentration on a flagstone, when suddenly he felt two large paws on his shoulders.Why all the concentration on genetic engineering?This concentration on industrial estates is not accidental.Take care not to relax your concentration on the way up. 2.concentration ofTests show high concentrations of chemicals in the water.California has the largest concentration of Vietnamese outside Vietnam.high/low concentrationsBut the atmospheres of the Jovian planets contain astronomical amounts, and high concentrations, of both helium-3 and deuterium.In the rat cerebral cortex in the absence of calmodulin, calcium has a negligible effect at low concentrations.Because of its wide use and toxicity at high concentrations, phenytoin is often the subject of overdose.The chemical, once used as an anesthetic, can be toxic if breathed in high concentrations.The same spectrum of peptides was also found in extracts of normal colon mucosa but in still lower concentrations.Do not exceed the stated dose in the belief that higher concentrations will be more effective.The high concentrations should not be a problem.Studies on people exposed to high concentrations of benzene in the workplace have shown it is linked with leukaemia.