26-02-2013, 12:18 PM
PERIODIC TABLE
PERIODIC.pptx (Size: 2.57 MB / Downloads: 46)
DOBEREINER’S TRIADS
When elements are arranged in the order of increasing atomic masses, groups of three elements [known as triads], having similar chemical properties are obtained. The atomic mass of the middle element of the triad being equal to the arithmetic mean of the atomic masses of the other two elements
Newland’s law of octaves
When elements are arranged in the order of increasing atomic masses, the properties of the 8th element[starting from a given element] are repetition of the properties of the first element.
Moseley’ periodic law
The properties of elements are a periodic function of their atomic number.
Moseley Discoveries
He discovered 4 blocks named s,p,d,f.
The square root of frequency[of x-ray] is directly proportional to atomic number.