Mass-to-charge ratio refers to the molecular or atomic mass number and "z" to the charge number of the ion; however, the quantity of "m"/"z" is dimensionless by definition. An ion of 100 atomic mass units ("m" = 100) carrying two charges ("z" = 2) will be observed at "m"/"z" = 50. In the 19th century, the mass-to-charge ratios of some ions were measured by electrochemical methods. In 1897, the mass-to-charge ratio of the electron was first measured by J. J. Thomson. By doing this, he showed that the electron was in fact a particle with a mass and a charge, and that
Ida (given name) may refer to: Ida (given name) Ida is a given name occurring independently in several cultures. In Germany, Ida is a female name derived from a Germanic word "id", meaning "labor, work". Alternately, it may be related to the name of the Old Norse goddess "Iðunn". Ida also occurs as an anglicisation of the Irish girl's given name Íde. Ida is a currently popular name in the Nordic countries and is among the top 10 names given to girls born in 2013 in Denmark. It was among the top 20 names for newborn girls in Norway in 2013 and among