concentration
//ˌkɒn.sənˈtreɪ.ʃən//
Noun
concentrationSingular
concentrationsPlural
1
The action or power of focusing one's attention or mental effort on a particular object or activity.
This task requires complete concentration.
2
A close gathering of people or things in one place; a dense collection.
There is a high concentration of restaurants in this area.
3
The relative amount of a particular substance contained within a solution or mixture.
The concentration of salt in seawater is about 3.5%.