Researchers can use a metric called the particle number concentration (PNC) to calculate the number of particles in a sample, such as the number of marbles in a jar. Researchers at the National ...

GCSE Chemistry worksheet on concentration with answers, covering concentration = mass ÷ volume and rearranging the relationship to calculate mass or volume. Questions use a range of numerical examples ...

A fully resourced GCSE Chemistry lesson designed to introduce one of the most challenging calculation topics in the GCSE specification. This lesson builds pupils’ confidence by breaking quantitative ...

Researchers at the National Institute of Standards and Technology (NIST) have developed a new mathematical formula to calculate the concentration of particles suspended in a solution. The new approach ...

Updates a guidance on estimating exposure of individuals to chemicals at hazardous waste sites with alternative methods for calculating the 95% upper confidence limit of the mean concentration.