Persistent behavior problems canaffect educational attainment, proper social development,employment, and the likelihood of criminality.The causes of childrenâs mental health problems arevaried and complex and include genetic makeup, childpoverty, maternal depression, and poor or abusivecare.
Paper chromatography is a technique for separating and identifying mixtures that are (or can be) coloured. It has been largely replaced by thin layer chromatography, but is still a powerful teaching tool. Double-way paper chromatography, also called 'two-dimensional chromatography', uses two solvents and rotates the paper 90Â° in between.
Thin layer chromatography is done exactly as it says - using a thin, uniform layer of silica gel or alumina coated onto a piece of glass, metal or rigid plastic. The silica gel (or the alumina) is the stationary phase. The stationary phase for thin layer chromatography also often contains a substance which fluoresces in UV light - for reasons you will see later. The mobile phase is a suitable liquid solvent or mixture of solvents.