Nitrogen (14.0 u) , phosphorus (31.0 u) andarsenic (74.9 u)havesimilarproperties. Do the they form aDobereiner 'striad? Comment .

Nitrogen (14.0 u) , phosphorus (31.0 u) andarsenic (74.9 u)havesimilar

1.	Nitrogen (14.0 u) , phosphorus (31.0 u) andarsenic (74.9 u)havesimilarproperties. Do the they form aDobereiner 'striad? Comment .
Answer» Solution :Sincethese elementhave similar propertiesthereforethey shouldform aDobereiner'striad. Butactuallythey donot because the atomicweight of middleelememtphosphorus(31 u)is not an arithmaticmean ofnitrogen (14.0 u)and ARSENIC(74. 9 u) . Arithmaticmean `(14 + 74. 9 ) /(2)= 44. 45 u `