There are lots of different substances but only just over a hundred elements. An element is a substance that is made up of only one kind of atom. The atoms in a particular element are the same as each ...

Gas mixtures of the highest calibre and purity are necessary for the calibration of analytical tools and gas detectors. Calibrations must be routinely checked to ensure that devices are performing as ...

The atmosphere is a mixture of gases. The atmosphere is mostly nitrogen (approximately 80%) and oxygen (approximately 20%). The remaining gases are found in much smaller proportions, such as carbon ...

Air emissions monitoring is a process that involves the continuous tracking of the concentrations of several gases, including SO 2, CO 2­, and NO. All of these gases are known pollutants that can have ...